640265648 has 40 divisors (see below), whose sum is σ = 1424521920. Its totient is φ = 275711040.

The previous prime is 640265623. The next prime is 640265653. The reversal of 640265648 is 846562046.

It is a super-3 number, since 3×640265648³ (a number of 27 digits) contains 333 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, 92390 + ... + 99077.

It is an arithmetic number, because the mean of its divisors is an integer number (35613048).

Almost surely, 2^640265648 is an apocalyptic number.

It is an amenable number.

640265648 is an abundant number, since it is smaller than the sum of its proper divisors (784256272).

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

640265648 is a wasteful number, since it uses less digits than its factorization.

640265648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191505 (or 191499 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 41.

The square root of 640265648 is about 25303.4710662391. The cubic root of 640265648 is about 861.8930931168.

The spelling of 640265648 in words is "six hundred forty million, two hundred sixty-five thousand, six hundred forty-eight".