31121431 has 16 divisors (see below), whose sum is σ = 34836480. Its totient is φ = 27565120.

The previous prime is 31121413. The next prime is 31121479. The reversal of 31121431 is 13412113.

It is not a de Polignac number, because 31121431 - 2⁵ = 31121399 is a prime.

It is a super-2 number, since 2×31121431² = 1937086934975522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31121401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 81066 + ... + 81448.

It is an arithmetic number, because the mean of its divisors is an integer number (2177280).

Almost surely, 2^31121431 is an apocalyptic number.

31121431 is a deficient number, since it is larger than the sum of its proper divisors (3715049).

31121431 is a wasteful number, since it uses less digits than its factorization.

31121431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 566.

The product of its digits is 72, while the sum is 16.

The square root of 31121431 is about 5578.6585305071. The cubic root of 31121431 is about 314.5477039464.

Adding to 31121431 its reverse (13412113), we get a palindrome (44533544).

The spelling of 31121431 in words is "thirty-one million, one hundred twenty-one thousand, four hundred thirty-one".