31243117 has 4 divisors (see below), whose sum is σ = 31265056. Its totient is φ = 31221180.

The previous prime is 31243111. The next prime is 31243123. The reversal of 31243117 is 71134213.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 71134213 = 3023 ⋅23531.

It is an interprime number because it is at equal distance from previous prime (31243111) and next prime (31243123).

It is a cyclic number.

It is not a de Polignac number, because 31243117 - 2¹⁵ = 31210349 is a prime.

It is a super-2 number, since 2×31243117² = 1952264719751378, 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 (31243111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8673 + ... + 11734.

It is an arithmetic number, because the mean of its divisors is an integer number (7816264).

Almost surely, 2^31243117 is an apocalyptic number.

It is an amenable number.

31243117 is a deficient number, since it is larger than the sum of its proper divisors (21939).

31243117 is a wasteful number, since it uses less digits than its factorization.

31243117 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21938.

The product of its digits is 504, while the sum is 22.

The square root of 31243117 is about 5589.5542756109. The cubic root of 31243117 is about 314.9571353448.

It can be divided in two parts, 3124 and 3117, that added together give a square (6241 = 79²).

The spelling of 31243117 in words is "thirty-one million, two hundred forty-three thousand, one hundred seventeen".