51720004 has 12 divisors (see below), whose sum is σ = 103440064. Its totient is φ = 22165704.

The previous prime is 51719981. The next prime is 51720029. The reversal of 51720004 is 40002715.

51720004 is an admirable number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 923544 + ... + 923599.

Almost surely, 2^51720004 is an apocalyptic number.

It is an amenable number.

51720004 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

51720004 is a wasteful number, since it uses less digits than its factorization.

51720004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1847154 (or 1847152 counting only the distinct ones).

The product of its (nonzero) digits is 280, while the sum is 19.

The square root of 51720004 is about 7191.6621166459. The cubic root of 51720004 is about 372.5799813241.

Adding to 51720004 its reverse (40002715), we get a palindrome (91722719).

The spelling of 51720004 in words is "fifty-one million, seven hundred twenty thousand, four".