252409864581 has 32 divisors (see below), whose sum is σ = 452499482880. Its totient is φ = 135749841408.

The previous prime is 252409864561. The next prime is 252409864591. The reversal of 252409864581 is 185468904252.

252409864581 is a `hidden beast` number, since 2 + 52 + 4 + 0 + 9 + 8 + 6 + 4 + 581 = 666.

It is not a de Polignac number, because 252409864581 - 2⁷ = 252409864453 is a prime.

It is a super-2 number, since 2×252409864581² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (252409864501) 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, 39276256 + ... + 39282681.

It is an arithmetic number, because the mean of its divisors is an integer number (14140608840).

Almost surely, 2^252409864581 is an apocalyptic number.

252409864581 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

252409864581 is a deficient number, since it is larger than the sum of its proper divisors (200089618299).

252409864581 is a wasteful number, since it uses less digits than its factorization.

252409864581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78558970 (or 78558964 counting only the distinct ones).

The product of its (nonzero) digits is 5529600, while the sum is 54.

The spelling of 252409864581 in words is "two hundred fifty-two billion, four hundred nine million, eight hundred sixty-four thousand, five hundred eighty-one".