31320145 has 16 divisors (see below), whose sum is σ = 39528720. Its totient is φ = 23788800.

The previous prime is 31320109. The next prime is 31320173. The reversal of 31320145 is 54102313.

It can be written as a sum of positive squares in 8 ways, for example, as 4787344 + 26532801 = 2188^2 + 5151^2 .

It is not a de Polignac number, because 31320145 - 2⁹ = 31319633 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7075 + ... + 10615.

It is an arithmetic number, because the mean of its divisors is an integer number (2470545).

Almost surely, 2^31320145 is an apocalyptic number.

It is an amenable number.

31320145 is a deficient number, since it is larger than the sum of its proper divisors (8208575).

31320145 is a wasteful number, since it uses less digits than its factorization.

31320145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3636.

The product of its (nonzero) digits is 360, while the sum is 19.

The square root of 31320145 is about 5596.4403865314. The cubic root of 31320145 is about 315.2157587921.

Adding to 31320145 its reverse (54102313), we get a palindrome (85422458).

The spelling of 31320145 in words is "thirty-one million, three hundred twenty thousand, one hundred forty-five".