211507220 has 12 divisors (see below), whose sum is σ = 444165204. Its totient is φ = 84602880.

The previous prime is 211507201. The next prime is 211507223. The reversal of 211507220 is 22705112.

It can be written as a sum of positive squares in 2 ways, for example, as 29203216 + 182304004 = 5404^2 + 13502^2 .

It is a super-2 number, since 2×211507220² = 89470608224256800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 10575361 = 211507220 / (2 + 1 + 1 + 5 + 0 + 7 + 2 + 2 + 0).

It is a junction number, because it is equal to n+sod(n) for n = 211507192 and 211507201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211507223) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5287661 + ... + 5287700.

It is an arithmetic number, because the mean of its divisors is an integer number (37013767).

Almost surely, 2^211507220 is an apocalyptic number.

211507220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

211507220 is an abundant number, since it is smaller than the sum of its proper divisors (232657984).

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

211507220 is a wasteful number, since it uses less digits than its factorization.

211507220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10575370 (or 10575368 counting only the distinct ones).

The product of its (nonzero) digits is 280, while the sum is 20.

The square root of 211507220 is about 14543.2877988438. The cubic root of 211507220 is about 595.8108381268.

The spelling of 211507220 in words is "two hundred eleven million, five hundred seven thousand, two hundred twenty".