31121965 has 32 divisors (see below), whose sum is σ = 44029440. Its totient is φ = 20680704.

The previous prime is 31121963. The next prime is 31121977. The reversal of 31121965 is 56912113.

It is a cyclic number.

It is not a de Polignac number, because 31121965 - 2¹ = 31121963 is a prime.

It is a super-2 number, since 2×31121965² = 1937153410922450, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31121963) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 302104 + ... + 302206.

It is an arithmetic number, because the mean of its divisors is an integer number (1375920).

Almost surely, 2^31121965 is an apocalyptic number.

31121965 is a gapful number since it is divisible by the number (35) formed by its first and last digit.

It is an amenable number.

31121965 is a deficient number, since it is larger than the sum of its proper divisors (12907475).

31121965 is a wasteful number, since it uses less digits than its factorization.

31121965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 301.

The product of its digits is 1620, while the sum is 28.

The square root of 31121965 is about 5578.7063912703. The cubic root of 31121965 is about 314.5495030016.

The spelling of 31121965 in words is "thirty-one million, one hundred twenty-one thousand, nine hundred sixty-five".