51215791 has 12 divisors (see below), whose sum is σ = 56517552. Its totient is φ = 46376000.

The previous prime is 51215789. The next prime is 51215803. The reversal of 51215791 is 19751215.

It is not a de Polignac number, because 51215791 - 2¹ = 51215789 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51215771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 36951 + ... + 38311.

It is an arithmetic number, because the mean of its divisors is an integer number (4709796).

Almost surely, 2^51215791 is an apocalyptic number.

51215791 is a deficient number, since it is larger than the sum of its proper divisors (5301761).

51215791 is a wasteful number, since it uses less digits than its factorization.

51215791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1694 (or 1683 counting only the distinct ones).

The product of its digits is 3150, while the sum is 31.

The square root of 51215791 is about 7156.5208726028. The cubic root of 51215791 is about 371.3652774158.

The spelling of 51215791 in words is "fifty-one million, two hundred fifteen thousand, seven hundred ninety-one".