21200412534 has 64 divisors (see below), whose sum is σ = 51873177600. Its totient is φ = 5641183008.

The previous prime is 21200412517. The next prime is 21200412559. The reversal of 21200412534 is 43521400212.

It is a super-2 number, since 2×21200412534² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 178062 + ... + 272225.

It is an arithmetic number, because the mean of its divisors is an integer number (810518400).

Almost surely, 2^21200412534 is an apocalyptic number.

21200412534 is an abundant number, since it is smaller than the sum of its proper divisors (30672765066).

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

21200412534 is a wasteful number, since it uses less digits than its factorization.

21200412534 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 450377.

The product of its (nonzero) digits is 1920, while the sum is 24.

Adding to 21200412534 its reverse (43521400212), we get a palindrome (64721812746).

The spelling of 21200412534 in words is "twenty-one billion, two hundred million, four hundred twelve thousand, five hundred thirty-four".