640626552 has 24 divisors (see below), whose sum is σ = 1735030440. Its totient is φ = 213542160.

The previous prime is 640626533. The next prime is 640626583. The reversal of 640626552 is 255626046.

640626552 is a `hidden beast` number, since 6 + 40 + 62 + 6 + 552 = 666.

It is a tau number, because it is divible by the number of its divisors (24).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4448724 + ... + 4448867.

It is an arithmetic number, because the mean of its divisors is an integer number (72292935).

Almost surely, 2^640626552 is an apocalyptic number.

It is an amenable number.

640626552 is an abundant number, since it is smaller than the sum of its proper divisors (1094403888).

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

640626552 is a wasteful number, since it uses less digits than its factorization.

640626552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8897603 (or 8897596 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 36.

The square root of 640626552 is about 25310.6015732538. The cubic root of 640626552 is about 862.0550062425.

The spelling of 640626552 in words is "six hundred forty million, six hundred twenty-six thousand, five hundred fifty-two".