521243320511421 has 12 divisors (see below), whose sum is σ = 752909878548672. Its totient is φ = 347494226992776.

The previous prime is 521243320511371. The next prime is 521243320511521. The reversal of 521243320511421 is 124115023342125.

521243320511421 is a `hidden beast` number, since 5 + 2 + 1 + 2 + 433 + 205 + 1 + 14 + 2 + 1 = 666.

It is not a de Polignac number, because 521243320511421 - 2⁶ = 521243320511357 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521243320511521) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 107497351 + ... + 112241556.

It is an arithmetic number, because the mean of its divisors is an integer number (62742489879056).

Almost surely, 2^{521243320511421} is an apocalyptic number.

It is an amenable number.

521243320511421 is a deficient number, since it is larger than the sum of its proper divisors (231666558037251).

521243320511421 is a wasteful number, since it uses less digits than its factorization.

521243320511421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 220002480 (or 220002477 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 36.

Adding to 521243320511421 its reverse (124115023342125), we get a palindrome (645358343853546).

The spelling of 521243320511421 in words is "five hundred twenty-one trillion, two hundred forty-three billion, three hundred twenty million, five hundred eleven thousand, four hundred twenty-one".