31117431 has 16 divisors (see below), whose sum is σ = 42624000. Its totient is φ = 20183328.

The previous prime is 31117417. The next prime is 31117439. The reversal of 31117431 is 13471113.

It is not a de Polignac number, because 31117431 - 2⁵ = 31117399 is a prime.

It is a super-2 number, since 2×31117431² = 1936589024079522, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 31117398 and 31117407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31117439) 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, 27505 + ... + 28613.

It is an arithmetic number, because the mean of its divisors is an integer number (2664000).

Almost surely, 2^31117431 is an apocalyptic number.

31117431 is a deficient number, since it is larger than the sum of its proper divisors (11506569).

31117431 is a wasteful number, since it uses less digits than its factorization.

31117431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1358.

The product of its digits is 252, while the sum is 21.

The square root of 31117431 is about 5578.3000098596. The cubic root of 31117431 is about 314.5342272233.

Adding to 31117431 its reverse (13471113), we get a palindrome (44588544).

The spelling of 31117431 in words is "thirty-one million, one hundred seventeen thousand, four hundred thirty-one".