51208137 has 6 divisors (see below), whose sum is σ = 73967322. Its totient is φ = 34138752.

The previous prime is 51208133. The next prime is 51208147. The reversal of 51208137 is 73180215.

It can be written as a sum of positive squares in only one way, i.e., 50466816 + 741321 = 7104^2 + 861^2 .

It is not a de Polignac number, because 51208137 - 2² = 51208133 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 51208137.

It is not an unprimeable number, because it can be changed into a prime (51208133) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2844888 + ... + 2844905.

It is an arithmetic number, because the mean of its divisors is an integer number (12327887).

Almost surely, 2^51208137 is an apocalyptic number.

It is an amenable number.

51208137 is a deficient number, since it is larger than the sum of its proper divisors (22759185).

51208137 is a wasteful number, since it uses less digits than its factorization.

51208137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5689799 (or 5689796 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The square root of 51208137 is about 7155.9860955706. The cubic root of 51208137 is about 371.3467767972.

The spelling of 51208137 in words is "fifty-one million, two hundred eight thousand, one hundred thirty-seven".