640520196 has 24 divisors (see below), whose sum is σ = 1497324864. Its totient is φ = 213109920.

The previous prime is 640520189. The next prime is 640520207. The reversal of 640520196 is 691025046.

It is a super-2 number, since 2×640520196² = 820532242967756832, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42840 + ... + 55823.

It is an arithmetic number, because the mean of its divisors is an integer number (62388536).

Almost surely, 2^640520196 is an apocalyptic number.

It is an amenable number.

640520196 is an abundant number, since it is smaller than the sum of its proper divisors (856804668).

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

640520196 is a wasteful number, since it uses less digits than its factorization.

640520196 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99211 (or 99209 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 33.

The square root of 640520196 is about 25308.5004692099. The cubic root of 640520196 is about 862.0072978461.

The spelling of 640520196 in words is "six hundred forty million, five hundred twenty thousand, one hundred ninety-six".