645256110164 has 12 divisors (see below), whose sum is σ = 1150503819444. Its totient is φ = 316540733184.

The previous prime is 645256110151. The next prime is 645256110199. The reversal of 645256110164 is 461011652546.

It can be written as a sum of positive squares in 2 ways, for example, as 381565644100 + 263690466064 = 617710^2 + 513508^2 .

It is a super-2 number, since 2×645256110164² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

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, 1521830237 + ... + 1521830660.

It is an arithmetic number, because the mean of its divisors is an integer number (95875318287).

Almost surely, 2^645256110164 is an apocalyptic number.

It is an amenable number.

645256110164 is a deficient number, since it is larger than the sum of its proper divisors (505247709280).

645256110164 is a wasteful number, since it uses less digits than its factorization.

645256110164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3043660954 (or 3043660952 counting only the distinct ones).

The product of its (nonzero) digits is 172800, while the sum is 41.

The spelling of 645256110164 in words is "six hundred forty-five billion, two hundred fifty-six million, one hundred ten thousand, one hundred sixty-four".