51439664 has 40 divisors (see below), whose sum is σ = 103767168. Its totient is φ = 24675840.

The previous prime is 51439651. The next prime is 51439673. The reversal of 51439664 is 46693415.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 67574 + ... + 68330.

Almost surely, 2^51439664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51439664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51883584).

51439664 is an abundant number, since it is smaller than the sum of its proper divisors (52327504).

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

51439664 is a wasteful number, since it uses less digits than its factorization.

51439664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 933 (or 927 counting only the distinct ones).

The product of its digits is 77760, while the sum is 38.

The square root of 51439664 is about 7172.1450069000. The cubic root of 51439664 is about 371.9055913351.

The spelling of 51439664 in words is "fifty-one million, four hundred thirty-nine thousand, six hundred sixty-four".