31904072 has 12 divisors (see below), whose sum is σ = 59850105. Its totient is φ = 15944048.

The previous prime is 31904057. The next prime is 31904077. The reversal of 31904072 is 27040913.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in 2 ways, for example, as 20921476 + 10982596 = 4574^2 + 3314^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=3994.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31904077) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 14978 + ... + 16974.

Almost surely, 2^31904072 is an apocalyptic number.

It is an amenable number.

31904072 is a deficient number, since it is larger than the sum of its proper divisors (27946033).

31904072 is an frugal number, since it uses more digits than its factorization.

31904072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4000 (or 1999 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 26.

The square root of 31904072 is about 5648.3689681181. The cubic root of 31904072 is about 317.1626507602.

Adding to 31904072 its reverse (27040913), we get a palindrome (58944985).

The spelling of 31904072 in words is "thirty-one million, nine hundred four thousand, seventy-two".