211431520520 has 32 divisors (see below), whose sum is σ = 518968278720. Its totient is φ = 76884189120.

The previous prime is 211431520507. The next prime is 211431520529. The reversal of 211431520520 is 25025134112.

It is a self number, because there is not a number n which added to its sum of digits gives 211431520520.

It is not an unprimeable number, because it can be changed into a prime (211431520529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 240262652 + ... + 240263531.

It is an arithmetic number, because the mean of its divisors is an integer number (16217758710).

Almost surely, 2^211431520520 is an apocalyptic number.

211431520520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

211431520520 is an abundant number, since it is smaller than the sum of its proper divisors (307536758200).

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

211431520520 is a wasteful number, since it uses less digits than its factorization.

211431520520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 480526205 (or 480526201 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 26.

Adding to 211431520520 its reverse (25025134112), we get a palindrome (236456654632).

The spelling of 211431520520 in words is "two hundred eleven billion, four hundred thirty-one million, five hundred twenty thousand, five hundred twenty".