31322681 has 4 divisors (see below), whose sum is σ = 33732132. Its totient is φ = 28913232.

The previous prime is 31322671. The next prime is 31322693. The reversal of 31322681 is 18622313.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18622313 = 307 ⋅60659.

It can be written as a sum of positive squares in 2 ways, for example, as 19009600 + 12313081 = 4360^2 + 3509^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31322681 is a prime.

It is a super-2 number, since 2×31322681² = 1962220690055522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31322681.

It is not an unprimeable number, because it can be changed into a prime (31322671) 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, 1204706 + ... + 1204731.

It is an arithmetic number, because the mean of its divisors is an integer number (8433033).

Almost surely, 2^31322681 is an apocalyptic number.

It is an amenable number.

31322681 is a deficient number, since it is larger than the sum of its proper divisors (2409451).

31322681 is a wasteful number, since it uses less digits than its factorization.

31322681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2409450.

The product of its digits is 1728, while the sum is 26.

The square root of 31322681 is about 5596.6669545364. Note that the first 3 decimals coincide. The cubic root of 31322681 is about 315.2242662622.

Adding to 31322681 its reverse (18622313), we get a palindrome (49944994).

The spelling of 31322681 in words is "thirty-one million, three hundred twenty-two thousand, six hundred eighty-one".