64635640 has 16 divisors (see below), whose sum is σ = 145430280. Its totient is φ = 25854240.

The previous prime is 64635629. The next prime is 64635679. The reversal of 64635640 is 4653646.

It is a junction number, because it is equal to n+sod(n) for n = 64635596 and 64635605.

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, 807906 + ... + 807985.

Almost surely, 2^64635640 is an apocalyptic number.

It is an amenable number.

64635640 is an abundant number, since it is smaller than the sum of its proper divisors (80794640).

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

64635640 is a wasteful number, since it uses less digits than its factorization.

64635640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1615902 (or 1615898 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 34.

The square root of 64635640 is about 8039.6293446900. The cubic root of 64635640 is about 401.3198899360.

The spelling of 64635640 in words is "sixty-four million, six hundred thirty-five thousand, six hundred forty".