31042521 has 12 divisors (see below), whose sum is σ = 46500272. Its totient is φ = 20694852.

The previous prime is 31042489. The next prime is 31042537. The reversal of 31042521 is 12524013.

It is not a de Polignac number, because 31042521 - 2⁵ = 31042489 is a prime.

It is a super-2 number, since 2×31042521² = 1927276220070882, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 31042494 and 31042503.

It is not an unprimeable number, because it can be changed into a prime (31042541) 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, 63631 + ... + 64116.

Almost surely, 2^31042521 is an apocalyptic number.

It is an amenable number.

31042521 is a deficient number, since it is larger than the sum of its proper divisors (15457751).

31042521 is an equidigital number, since it uses as much as digits as its factorization.

31042521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127762 (or 127750 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 31042521 is about 5571.5815528448. The cubic root of 31042521 is about 314.2816282723.

Adding to 31042521 its reverse (12524013), we get a palindrome (43566534).

It can be divided in two parts, 3104 and 2521, that added together give a square (5625 = 75²).

The spelling of 31042521 in words is "thirty-one million, forty-two thousand, five hundred twenty-one".