31165421 has 24 divisors (see below), whose sum is σ = 37537920. Its totient is φ = 25788672.

The previous prime is 31165399. The next prime is 31165439. The reversal of 31165421 is 12456113.

It is not a de Polignac number, because 31165421 - 2⁶ = 31165357 is a prime.

It is a super-2 number, since 2×31165421² = 1942566932214482, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31165441) 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 23 ways as a sum of consecutive naturals, for example, 321245 + ... + 321341.

It is an arithmetic number, because the mean of its divisors is an integer number (1564080).

Almost surely, 2^31165421 is an apocalyptic number.

It is an amenable number.

31165421 is a deficient number, since it is larger than the sum of its proper divisors (6372499).

31165421 is an equidigital number, since it uses as much as digits as its factorization.

31165421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 273 (or 266 counting only the distinct ones).

The product of its digits is 720, while the sum is 23.

The square root of 31165421 is about 5582.5998423674. The cubic root of 31165421 is about 314.6958380850.

The spelling of 31165421 in words is "thirty-one million, one hundred sixty-five thousand, four hundred twenty-one".