212012640 has 576 divisors, whose sum is σ = 924618240. Its totient is φ = 44789760.

The previous prime is 212012639. The next prime is 212012641. The reversal of 212012640 is 46210212.

212012640 is a `hidden beast` number, since 2 + 1 + 20 + 1 + 2 + 640 = 666.

It is an interprime number because it is at equal distance from previous prime (212012639) and next prime (212012641).

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 (212012641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 5171020 + ... + 5171060.

It is an arithmetic number, because the mean of its divisors is an integer number (1605240).

Almost surely, 2^212012640 is an apocalyptic number.

212012640 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 212012640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (462309120).

212012640 is an abundant number, since it is smaller than the sum of its proper divisors (712605600).

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

212012640 is a wasteful number, since it uses less digits than its factorization.

212012640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97 (or 77 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 212012640 is about 14560.6538314734. The cubic root of 212012640 is about 596.2850459999.

Adding to 212012640 its reverse (46210212), we get a palindrome (258222852).

The spelling of 212012640 in words is "two hundred twelve million, twelve thousand, six hundred forty".