64397940 has 48 divisors (see below), whose sum is σ = 181160448. Its totient is φ = 17092224.

The previous prime is 64397933. The next prime is 64397941. The reversal of 64397940 is 4979346.

It is a junction number, because it is equal to n+sod(n) for n = 64397892 and 64397901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64397941) 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, 10974 + ... + 15786.

It is an arithmetic number, because the mean of its divisors is an integer number (3774176).

Almost surely, 2^64397940 is an apocalyptic number.

64397940 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

64397940 is an abundant number, since it is smaller than the sum of its proper divisors (116762508).

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

64397940 is a wasteful number, since it uses less digits than its factorization.

64397940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5048 (or 5046 counting only the distinct ones).

The product of its (nonzero) digits is 163296, while the sum is 42.

The square root of 64397940 is about 8024.8327085367. The cubic root of 64397940 is about 400.8273293025.

The spelling of 64397940 in words is "sixty-four million, three hundred ninety-seven thousand, nine hundred forty".