642567557531 has 2 divisors, whose sum is σ = 642567557532. Its totient is φ = 642567557530.

The previous prime is 642567557521. The next prime is 642567557579. The reversal of 642567557531 is 135755765246.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 642567557531 - 2²² = 642563363227 is a prime.

It is a super-2 number, since 2×642567557531² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (642567557521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321283778765 + 321283778766.

It is an arithmetic number, because the mean of its divisors is an integer number (321283778766).

Almost surely, 2^642567557531 is an apocalyptic number.

642567557531 is a deficient number, since it is larger than the sum of its proper divisors (1).

642567557531 is an equidigital number, since it uses as much as digits as its factorization.

642567557531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 26460000, while the sum is 56.

The spelling of 642567557531 in words is "six hundred forty-two billion, five hundred sixty-seven million, five hundred fifty-seven thousand, five hundred thirty-one".