51215660 has 12 divisors (see below), whose sum is σ = 107552928. Its totient is φ = 20486256.

The previous prime is 51215651. The next prime is 51215663. The reversal of 51215660 is 6651215.

It is not an unprimeable number, because it can be changed into a prime (51215663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1280372 + ... + 1280411.

It is an arithmetic number, because the mean of its divisors is an integer number (8962744).

Almost surely, 2^51215660 is an apocalyptic number.

It is an amenable number.

51215660 is an abundant number, since it is smaller than the sum of its proper divisors (56337268).

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

51215660 is a wasteful number, since it uses less digits than its factorization.

51215660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2560792 (or 2560790 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 26.

The square root of 51215660 is about 7156.5117201050. The cubic root of 51215660 is about 371.3649607889.

Adding to 51215660 its reverse (6651215), we get a palindrome (57866875).

The spelling of 51215660 in words is "fifty-one million, two hundred fifteen thousand, six hundred sixty".