51831819 has 20 divisors (see below), whose sum is σ = 83385456. Its totient is φ = 31895856.

The previous prime is 51831809. The next prime is 51831841. The reversal of 51831819 is 91813815.

It is not a de Polignac number, because 51831819 - 2¹² = 51827723 is a prime.

It is a super-2 number, since 2×51831819² = 5373074921697522, which contains 22 as substring.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (51831809) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 23559 + ... + 25664.

Almost surely, 2^51831819 is an apocalyptic number.

51831819 is a deficient number, since it is larger than the sum of its proper divisors (31553637).

51831819 is a wasteful number, since it uses less digits than its factorization.

51831819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49248 (or 49239 counting only the distinct ones).

The product of its digits is 8640, while the sum is 36.

The square root of 51831819 is about 7199.4318525839. The cubic root of 51831819 is about 372.8482852774.

It can be divided in two parts, 51831 and 819, that added together give a triangular number (52650 = T₃₂₄).

The spelling of 51831819 in words is "fifty-one million, eight hundred thirty-one thousand, eight hundred nineteen".