64979440 has 40 divisors (see below), whose sum is σ = 159967440. Its totient is φ = 24462336.

The previous prime is 64979429. The next prime is 64979443. The reversal of 64979440 is 4497946.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64979443) 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, 22530 + ... + 25249.

It is an arithmetic number, because the mean of its divisors is an integer number (3999186).

Almost surely, 2^64979440 is an apocalyptic number.

It is an amenable number.

64979440 is an abundant number, since it is smaller than the sum of its proper divisors (94988000).

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

64979440 is a wasteful number, since it uses less digits than its factorization.

64979440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47809 (or 47803 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 43.

The square root of 64979440 is about 8060.9825703819. The cubic root of 64979440 is about 402.0301785055.

It can be divided in two parts, 649 and 79440, that added together give a square (80089 = 283²).

The spelling of 64979440 in words is "sixty-four million, nine hundred seventy-nine thousand, four hundred forty".