211215240 has 192 divisors, whose sum is σ = 716517360. Its totient is φ = 53913600.

The previous prime is 211215239. The next prime is 211215241. The reversal of 211215240 is 42512112.

211215240 is a `hidden beast` number, since 21 + 121 + 524 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (211215239) and next prime (211215241).

It can be written as a sum of positive squares in 8 ways, for example, as 172501956 + 38713284 = 13134^2 + 6222^2 .

It is a super-2 number, since 2×211215240² = 89223755216515200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211215241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1345242 + ... + 1345398.

Almost surely, 2^211215240 is an apocalyptic number.

211215240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 211215240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (358258680).

211215240 is an abundant number, since it is smaller than the sum of its proper divisors (505302120).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

211215240 is a wasteful number, since it uses less digits than its factorization.

211215240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 312 (or 305 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 211215240 is about 14533.2460242026. The cubic root of 211215240 is about 595.5365449510.

Adding to 211215240 its reverse (42512112), we get a palindrome (253727352).

The spelling of 211215240 in words is "two hundred eleven million, two hundred fifteen thousand, two hundred forty".