51000031 has 4 divisors (see below), whose sum is σ = 51372432. Its totient is φ = 50627632.

The previous prime is 50999999. The next prime is 51000041. The reversal of 51000031 is 13000015.

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

It is a cyclic number.

It is not a de Polignac number, because 51000031 - 2⁵ = 50999999 is a prime.

It is a super-2 number, since 2×51000031² = 5202006324001922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 50999981 and 51000017.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51000041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 185995 + ... + 186268.

It is an arithmetic number, because the mean of its divisors is an integer number (12843108).

Almost surely, 2^51000031 is an apocalyptic number.

51000031 is a deficient number, since it is larger than the sum of its proper divisors (372401).

51000031 is a wasteful number, since it uses less digits than its factorization.

51000031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 372400.

The product of its (nonzero) digits is 15, while the sum is 10.

The square root of 51000031 is about 7141.4305989767. The cubic root of 51000031 is about 370.8430520647.

Adding to 51000031 its reverse (13000015), we get a palindrome (64000046).

The spelling of 51000031 in words is "fifty-one million, thirty-one", and thus it is an aban number and an uban number.