51515906 has 32 divisors (see below), whose sum is σ = 87429888. Its totient is φ = 22587840.

The previous prime is 51515869. The next prime is 51515923. The reversal of 51515906 is 60951515.

It is a Smith number, since the sum of its digits (32) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 165491 + ... + 165801.

It is an arithmetic number, because the mean of its divisors is an integer number (2732184).

Almost surely, 2^51515906 is an apocalyptic number.

51515906 is a deficient number, since it is larger than the sum of its proper divisors (35913982).

51515906 is a wasteful number, since it uses less digits than its factorization.

51515906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 626.

The product of its (nonzero) digits is 6750, while the sum is 32.

The square root of 51515906 is about 7177.4581851795. The cubic root of 51515906 is about 372.0892422806.

The spelling of 51515906 in words is "fifty-one million, five hundred fifteen thousand, nine hundred six".