21255216400526 has 16 divisors (see below), whose sum is σ = 31944608948400. Its totient is φ = 10607024469888.

The previous prime is 21255216400469. The next prime is 21255216400541. The reversal of 21255216400526 is 62500461255212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1087766 + ... + 6610118.

It is an arithmetic number, because the mean of its divisors is an integer number (1996538059275).

Almost surely, 2^{21255216400526} is an apocalyptic number.

21255216400526 is a deficient number, since it is larger than the sum of its proper divisors (10689392547874).

21255216400526 is a wasteful number, since it uses less digits than its factorization.

21255216400526 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5526083.

The product of its (nonzero) digits is 288000, while the sum is 41.

Adding to 21255216400526 its reverse (62500461255212), we get a palindrome (83755677655738).

The spelling of 21255216400526 in words is "twenty-one trillion, two hundred fifty-five billion, two hundred sixteen million, four hundred thousand, five hundred twenty-six".