51531965 has 8 divisors (see below), whose sum is σ = 62159928. Its totient is φ = 41011200.

The previous prime is 51531943. The next prime is 51531989. The reversal of 51531965 is 56913515.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 8281 + 51523684 = 91^2 + 7178^2 .

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

It is not a de Polignac number, because 51531965 - 2¹⁸ = 51269821 is a prime.

It is a super-2 number, since 2×51531965² = 5311086833522450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25736 + ... + 27665.

It is an arithmetic number, because the mean of its divisors is an integer number (7769991).

Almost surely, 2^51531965 is an apocalyptic number.

It is an amenable number.

51531965 is a deficient number, since it is larger than the sum of its proper divisors (10627963).

51531965 is a wasteful number, since it uses less digits than its factorization.

51531965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53599.

The product of its digits is 20250, while the sum is 35.

The square root of 51531965 is about 7178.5768088111. The cubic root of 51531965 is about 372.1279019284.

The spelling of 51531965 in words is "fifty-one million, five hundred thirty-one thousand, nine hundred sixty-five".