51689931 has 8 divisors (see below), whose sum is σ = 69098640. Its totient is φ = 34370592.

The previous prime is 51689923. The next prime is 51689933. The reversal of 51689931 is 13998615.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 51689931 - 2³ = 51689923 is a prime.

It is a super-2 number, since 2×51689931² = 5343697933569522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (51689933) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20980 + ... + 23313.

It is an arithmetic number, because the mean of its divisors is an integer number (8637330).

Almost surely, 2^51689931 is an apocalyptic number.

51689931 is a deficient number, since it is larger than the sum of its proper divisors (17408709).

51689931 is a wasteful number, since it uses less digits than its factorization.

51689931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44685.

The product of its digits is 58320, while the sum is 42.

The square root of 51689931 is about 7189.5709885917. The cubic root of 51689931 is about 372.5077541439.

The spelling of 51689931 in words is "fifty-one million, six hundred eighty-nine thousand, nine hundred thirty-one".