51642531 has 12 divisors (see below), whose sum is σ = 75133240. Its totient is φ = 34179840.

The previous prime is 51642529. The next prime is 51642581. The reversal of 51642531 is 13524615.

51642531 is nontrivially palindromic in base 2.

It is not a de Polignac number, because 51642531 - 2¹ = 51642529 is a prime.

It is a super-2 number, since 2×51642531² = 5333902016171922, 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 = 51642495 and 51642504.

It is not an unprimeable number, because it can be changed into a prime (51642581) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19390 + ... + 21891.

Almost surely, 2^51642531 is an apocalyptic number.

51642531 is a deficient number, since it is larger than the sum of its proper divisors (23490709).

51642531 is a wasteful number, since it uses less digits than its factorization.

51642531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41426 (or 41423 counting only the distinct ones).

The product of its digits is 3600, while the sum is 27.

The square root of 51642531 is about 7186.2737910547. The cubic root of 51642531 is about 372.3938553174.

The spelling of 51642531 in words is "fifty-one million, six hundred forty-two thousand, five hundred thirty-one".