645639972258 has 8 divisors (see below), whose sum is σ = 1291279944528. Its totient is φ = 215213324084.

The previous prime is 645639972239. The next prime is 645639972269. The reversal of 645639972258 is 852279936546.

It is a sphenic number, since it is the product of 3 distinct primes.

645639972258 is an admirable number.

It is a super-2 number, since 2×645639972258² (a number of 24 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53803331016 + ... + 53803331027.

It is an arithmetic number, because the mean of its divisors is an integer number (161409993066).

Almost surely, 2^645639972258 is an apocalyptic number.

645639972258 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

645639972258 is a wasteful number, since it uses less digits than its factorization.

645639972258 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107606662048.

The product of its digits is 195955200, while the sum is 66.

The spelling of 645639972258 in words is "six hundred forty-five billion, six hundred thirty-nine million, nine hundred seventy-two thousand, two hundred fifty-eight".