51215775 has 24 divisors (see below), whose sum is σ = 91192080. Its totient is φ = 25213440.

The previous prime is 51215771. The next prime is 51215777. The reversal of 51215775 is 57751215.

It is not a de Polignac number, because 51215775 - 2² = 51215771 is a prime.

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 23 ways as a sum of consecutive naturals, for example, 25290 + ... + 27239.

It is an arithmetic number, because the mean of its divisors is an integer number (3799670).

Almost surely, 2^51215775 is an apocalyptic number.

51215775 is a deficient number, since it is larger than the sum of its proper divisors (39976305).

51215775 is a wasteful number, since it uses less digits than its factorization.

51215775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52555 (or 52550 counting only the distinct ones).

The product of its digits is 12250, while the sum is 33.

The square root of 51215775 is about 7156.5197547411. The cubic root of 51215775 is about 371.3652387438.

The spelling of 51215775 in words is "fifty-one million, two hundred fifteen thousand, seven hundred seventy-five".