64605840 has 80 divisors (see below), whose sum is σ = 215694528. Its totient is φ = 15902208.

The previous prime is 64605839. The next prime is 64605847. The reversal of 64605840 is 4850646.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (64605847) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7234 + ... + 13473.

Almost surely, 2^64605840 is an apocalyptic number.

64605840 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

64605840 is an abundant number, since it is smaller than the sum of its proper divisors (151088688).

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

64605840 is a wasteful number, since it uses less digits than its factorization.

64605840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20736 (or 20730 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 33.

The square root of 64605840 is about 8037.7758117529. The cubic root of 64605840 is about 401.2582048186.

The spelling of 64605840 in words is "sixty-four million, six hundred five thousand, eight hundred forty".