51568138 has 4 divisors (see below), whose sum is σ = 77352210. Its totient is φ = 25784068.

The previous prime is 51568133. The next prime is 51568141. The reversal of 51568138 is 83186515.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 47018449 + 4549689 = 6857^2 + 2133^2 .

It is a junction number, because it is equal to n+sod(n) for n = 51568097 and 51568106.

It is not an unprimeable number, because it can be changed into a prime (51568133) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12892033 + ... + 12892036.

Almost surely, 2^51568138 is an apocalyptic number.

51568138 is a deficient number, since it is larger than the sum of its proper divisors (25784072).

51568138 is a wasteful number, since it uses less digits than its factorization.

51568138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25784071.

The product of its digits is 28800, while the sum is 37.

The square root of 51568138 is about 7181.0958773714. The cubic root of 51568138 is about 372.2149536199.

The spelling of 51568138 in words is "fifty-one million, five hundred sixty-eight thousand, one hundred thirty-eight".