31530531 has 4 divisors (see below), whose sum is σ = 42040712. Its totient is φ = 21020352.

The previous prime is 31530523. The next prime is 31530571. The reversal of 31530531 is 13503513.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13503513 = 3 ⋅4501171.

It is not a de Polignac number, because 31530531 - 2³ = 31530523 is a prime.

It is a super-2 number, since 2×31530531² = 1988348770283922, 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 = 31530498 and 31530507.

It is not an unprimeable number, because it can be changed into a prime (31530571) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5255086 + ... + 5255091.

It is an arithmetic number, because the mean of its divisors is an integer number (10510178).

Almost surely, 2^31530531 is an apocalyptic number.

31530531 is a deficient number, since it is larger than the sum of its proper divisors (10510181).

31530531 is a wasteful number, since it uses less digits than its factorization.

31530531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10510180.

The product of its (nonzero) digits is 675, while the sum is 21.

The square root of 31530531 is about 5615.2053390771. The cubic root of 31530531 is about 315.9199812078.

The spelling of 31530531 in words is "thirty-one million, five hundred thirty thousand, five hundred thirty-one".