31122121 has 12 divisors (see below), whose sum is σ = 33388092. Its totient is φ = 29001728.

The previous prime is 31122101. The next prime is 31122173. The reversal of 31122121 is 12122113.

It can be written as a sum of positive squares in 6 ways, for example, as 164025 + 30958096 = 405^2 + 5564^2 .

It is not a de Polignac number, because 31122121 - 2⁵ = 31122089 is a prime.

It is a super-3 number, since 3×31122121³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31122101) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 32181 + ... + 33133.

It is an arithmetic number, because the mean of its divisors is an integer number (2782341).

Almost surely, 2^31122121 is an apocalyptic number.

It is an amenable number.

31122121 is a deficient number, since it is larger than the sum of its proper divisors (2265971).

31122121 is a wasteful number, since it uses less digits than its factorization.

31122121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1100 (or 1083 counting only the distinct ones).

The product of its digits is 24, while the sum is 13.

The square root of 31122121 is about 5578.7203729888. The cubic root of 31122121 is about 314.5500285644.

Adding to 31122121 its reverse (12122113), we get a palindrome (43244234).

The spelling of 31122121 in words is "thirty-one million, one hundred twenty-two thousand, one hundred twenty-one".