64623640 has 16 divisors (see below), whose sum is σ = 145403280. Its totient is φ = 25849440.

The previous prime is 64623599. The next prime is 64623641. The reversal of 64623640 is 4632646.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64623641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 807756 + ... + 807835.

It is an arithmetic number, because the mean of its divisors is an integer number (9087705).

Almost surely, 2^64623640 is an apocalyptic number.

It is an amenable number.

64623640 is an abundant number, since it is smaller than the sum of its proper divisors (80779640).

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

64623640 is a wasteful number, since it uses less digits than its factorization.

64623640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1615602 (or 1615598 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 31.

The square root of 64623640 is about 8038.8830069855. The cubic root of 64623640 is about 401.2950525721.

The spelling of 64623640 in words is "sixty-four million, six hundred twenty-three thousand, six hundred forty".