31321431 has 16 divisors (see below), whose sum is σ = 46489600. Its totient is φ = 20841624.

The previous prime is 31321427. The next prime is 31321441. The reversal of 31321431 is 13412313.

It is not a de Polignac number, because 31321431 - 2² = 31321427 is a prime.

It is a super-2 number, since 2×31321431² = 1962064079775522, 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 (31321441) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23850 + ... + 25128.

It is an arithmetic number, because the mean of its divisors is an integer number (2905600).

Almost surely, 2^31321431 is an apocalyptic number.

31321431 is a deficient number, since it is larger than the sum of its proper divisors (15168169).

31321431 is a wasteful number, since it uses less digits than its factorization.

31321431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2195 (or 2189 counting only the distinct ones).

The product of its digits is 216, while the sum is 18.

The square root of 31321431 is about 5596.5552798128. Note that the first 3 decimals coincide. The cubic root of 31321431 is about 315.2200729688.

Adding to 31321431 its reverse (13412313), we get a palindrome (44733744).

The spelling of 31321431 in words is "thirty-one million, three hundred twenty-one thousand, four hundred thirty-one".