521400113455221 has 96 divisors (see below), whose sum is σ = 1055165447411712. Its totient is φ = 239151509182080.

The previous prime is 521400113455201. The next prime is 521400113455271. The reversal of 521400113455221 is 122554311004125.

521400113455221 is a `hidden beast` number, since 5 + 2 + 1 + 40 + 0 + 11 + 34 + 552 + 21 = 666.

It is not a de Polignac number, because 521400113455221 - 2⁵ = 521400113455189 is a prime.

It is a super-2 number, since 2×521400113455221² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521400113455201) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1257955195 + ... + 1258369608.

It is an arithmetic number, because the mean of its divisors is an integer number (10991306743872).

Almost surely, 2^{521400113455221} is an apocalyptic number.

It is an amenable number.

521400113455221 is an abundant number, since it is smaller than the sum of its proper divisors (533765333956491).

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

521400113455221 is a wasteful number, since it uses less digits than its factorization.

521400113455221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2516324863 (or 2516324860 counting only the distinct ones).

The product of its (nonzero) digits is 48000, while the sum is 36.

Adding to 521400113455221 its reverse (122554311004125), we get a palindrome (643954424459346).

The spelling of 521400113455221 in words is "five hundred twenty-one trillion, four hundred billion, one hundred thirteen million, four hundred fifty-five thousand, two hundred twenty-one".