31165121 has 6 divisors (see below), whose sum is σ = 33747030. Its totient is φ = 28767648.

The previous prime is 31165109. The next prime is 31165133. The reversal of 31165121 is 12156113.

It is an interprime number because it is at equal distance from previous prime (31165109) and next prime (31165133).

It can be written as a sum of positive squares in 3 ways, for example, as 2958400 + 28206721 = 1720^2 + 5311^2 .

It is not a de Polignac number, because 31165121 - 2¹⁰ = 31164097 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31165093 and 31165102.

It is not an unprimeable number, because it can be changed into a prime (31165151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 92036 + ... + 92373.

It is an arithmetic number, because the mean of its divisors is an integer number (5624505).

Almost surely, 2^31165121 is an apocalyptic number.

It is an amenable number.

31165121 is a deficient number, since it is larger than the sum of its proper divisors (2581909).

31165121 is a wasteful number, since it uses less digits than its factorization.

31165121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 184435 (or 184422 counting only the distinct ones).

The product of its digits is 180, while the sum is 20.

The square root of 31165121 is about 5582.5729731012. The cubic root of 31165121 is about 314.6948283222.

The spelling of 31165121 in words is "thirty-one million, one hundred sixty-five thousand, one hundred twenty-one".