51919831 has 4 divisors (see below), whose sum is σ = 53710200. Its totient is φ = 50129464.

The previous prime is 51919811. The next prime is 51919859. The reversal of 51919831 is 13891915.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13891915 = 5 ⋅2778383.

It is a cyclic number.

It is not a de Polignac number, because 51919831 - 2¹⁵ = 51887063 is a prime.

It is a super-2 number, since 2×51919831² = 5391337702137122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51919801) 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, 895141 + ... + 895198.

It is an arithmetic number, because the mean of its divisors is an integer number (13427550).

Almost surely, 2^51919831 is an apocalyptic number.

51919831 is a deficient number, since it is larger than the sum of its proper divisors (1790369).

51919831 is a wasteful number, since it uses less digits than its factorization.

51919831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1790368.

The product of its digits is 9720, while the sum is 37.

The square root of 51919831 is about 7205.5416867852. The cubic root of 51919831 is about 373.0592018387.

The spelling of 51919831 in words is "fifty-one million, nine hundred nineteen thousand, eight hundred thirty-one".