31904145 has 128 divisors (see below), whose sum is σ = 72576000. Its totient is φ = 13208832.

The previous prime is 31904143. The next prime is 31904179. The reversal of 31904145 is 54140913.

It is not a de Polignac number, because 31904145 - 2¹ = 31904143 is a prime.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31904143) 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 127 ways as a sum of consecutive naturals, for example, 601939 + ... + 601991.

It is an arithmetic number, because the mean of its divisors is an integer number (567000).

Almost surely, 2^31904145 is an apocalyptic number.

31904145 is a gapful number since it is divisible by the number (35) formed by its first and last digit.

It is an amenable number.

31904145 is an abundant number, since it is smaller than the sum of its proper divisors (40671855).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31904145 is a wasteful number, since it uses less digits than its factorization.

31904145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101 (or 81 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 31904145 is about 5648.3754301569. The cubic root of 31904145 is about 317.1628926610.

The spelling of 31904145 in words is "thirty-one million, nine hundred four thousand, one hundred forty-five".