64685840 has 40 divisors (see below), whose sum is σ = 155251968. Its totient is φ = 25038720.

The previous prime is 64685839. The next prime is 64685849. The reversal of 64685840 is 4858646.

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

It is not an unprimeable number, because it can be changed into a prime (64685849) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10562 + ... + 15521.

Almost surely, 2^64685840 is an apocalyptic number.

It is an amenable number.

64685840 is an abundant number, since it is smaller than the sum of its proper divisors (90566128).

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

64685840 is a wasteful number, since it uses less digits than its factorization.

64685840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26127 (or 26121 counting only the distinct ones).

The product of its (nonzero) digits is 184320, while the sum is 41.

The square root of 64685840 is about 8042.7507732119. The cubic root of 64685840 is about 401.4237595922.

The spelling of 64685840 in words is "sixty-four million, six hundred eighty-five thousand, eight hundred forty".