64871920 has 40 divisors (see below), whose sum is σ = 151240320. Its totient is φ = 25877760.

The previous prime is 64871897. The next prime is 64871921. The reversal of 64871920 is 2917846.

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

It is a self number, because there is not a number n which added to its sum of digits gives 64871920.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64871921) 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, 36001 + ... + 37759.

It is an arithmetic number, because the mean of its divisors is an integer number (3781008).

Almost surely, 2^64871920 is an apocalyptic number.

It is an amenable number.

64871920 is an abundant number, since it is smaller than the sum of its proper divisors (86368400).

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

64871920 is a wasteful number, since it uses less digits than its factorization.

64871920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2233 (or 2227 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 37.

The square root of 64871920 is about 8054.3106471007. The cubic root of 64871920 is about 401.8083126939.

The spelling of 64871920 in words is "sixty-four million, eight hundred seventy-one thousand, nine hundred twenty".