640190000 has 50 divisors (see below), whose sum is σ = 1549988220. Its totient is φ = 256072000.

The previous prime is 640189999. The next prime is 640190069. The reversal of 640190000 is 91046.

It is a tau number, because it is divible by the number of its divisors (50).

It is a super-2 number, since 2×640190000² = 819686472200000000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 22010 + ... + 42009.

Almost surely, 2^640190000 is an apocalyptic number.

It is an amenable number.

640190000 is an abundant number, since it is smaller than the sum of its proper divisors (909798220).

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

640190000 is an equidigital number, since it uses as much as digits as its factorization.

640190000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64047 (or 64026 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 640190000 is about 25301.9762074032. The cubic root of 640190000 is about 861.8591472815.

The spelling of 640190000 in words is "six hundred forty million, one hundred ninety thousand".