31121013 has 32 divisors (see below), whose sum is σ = 52070400. Its totient is φ = 16061760.

The previous prime is 31120997. The next prime is 31121021. The reversal of 31121013 is 31012113.

It is not a de Polignac number, because 31121013 - 2⁴ = 31120997 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31121013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31121063) 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 31 ways as a sum of consecutive naturals, for example, 45631 + ... + 46307.

It is an arithmetic number, because the mean of its divisors is an integer number (1627200).

Almost surely, 2^31121013 is an apocalyptic number.

31121013 is a gapful number since it is divisible by the number (33) formed by its first and last digit.

It is an amenable number.

31121013 is a deficient number, since it is larger than the sum of its proper divisors (20949387).

31121013 is a wasteful number, since it uses less digits than its factorization.

31121013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 897.

The product of its (nonzero) digits is 18, while the sum is 12.

The square root of 31121013 is about 5578.6210661776. The cubic root of 31121013 is about 314.5462956829.

Adding to 31121013 its reverse (31012113), we get a palindrome (62133126).

Subtracting from 31121013 its reverse (31012113), we obtain a square (108900 = 330²).

The spelling of 31121013 in words is "thirty-one million, one hundred twenty-one thousand, thirteen".