64623440 has 40 divisors (see below), whose sum is σ = 171715200. Its totient is φ = 22156416.

The previous prime is 64623431. The next prime is 64623509. The reversal of 64623440 is 4432646.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

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, 57140 + ... + 58259.

It is an arithmetic number, because the mean of its divisors is an integer number (4292880).

Almost surely, 2^64623440 is an apocalyptic number.

It is an amenable number.

64623440 is an abundant number, since it is smaller than the sum of its proper divisors (107091760).

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

64623440 is a wasteful number, since it uses less digits than its factorization.

64623440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115419 (or 115413 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 29.

The square root of 64623440 is about 8038.8705674367. The cubic root of 64623440 is about 401.2946385900.

The spelling of 64623440 in words is "sixty-four million, six hundred twenty-three thousand, four hundred forty".