521666426463 has 32 divisors (see below), whose sum is σ = 867794973696. Its totient is φ = 271395318528.

The previous prime is 521666426453. The next prime is 521666426467. The reversal of 521666426463 is 364624666125.

It is not a de Polignac number, because 521666426463 - 2⁸ = 521666426207 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521666426467) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13068195 + ... + 13108052.

It is an arithmetic number, because the mean of its divisors is an integer number (27118592928).

Almost surely, 2^521666426463 is an apocalyptic number.

521666426463 is a deficient number, since it is larger than the sum of its proper divisors (346128547233).

521666426463 is a wasteful number, since it uses less digits than its factorization.

521666426463 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26176343.

The product of its digits is 7464960, while the sum is 51.

The spelling of 521666426463 in words is "five hundred twenty-one billion, six hundred sixty-six million, four hundred twenty-six thousand, four hundred sixty-three".