31864145 has 16 divisors (see below), whose sum is σ = 38879568. Its totient is φ = 25067520.

The previous prime is 31864139. The next prime is 31864153. The reversal of 31864145 is 54146813.

31864145 = 3991² + 3992².

It can be written as a sum of positive squares in 8 ways, for example, as 43264 + 31820881 = 208^2 + 5641^2 .

It is not a de Polignac number, because 31864145 - 2¹⁰ = 31863121 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 123857 + ... + 124113.

It is an arithmetic number, because the mean of its divisors is an integer number (2429973).

Almost surely, 2^31864145 is an apocalyptic number.

31864145 is the 3992-nd centered square number.

It is an amenable number.

31864145 is a deficient number, since it is larger than the sum of its proper divisors (7015423).

31864145 is a wasteful number, since it uses less digits than its factorization.

31864145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 580.

The product of its digits is 11520, while the sum is 32.

The square root of 31864145 is about 5644.8334785005. The cubic root of 31864145 is about 317.0302889786.

The spelling of 31864145 in words is "thirty-one million, eight hundred sixty-four thousand, one hundred forty-five".