31145225 has 12 divisors (see below), whose sum is σ = 38862096. Its totient is φ = 24760080.

The previous prime is 31145221. The next prime is 31145227. The reversal of 31145225 is 52254113.

It is not a de Polignac number, because 31145225 - 2² = 31145221 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31145225.

It is not an unprimeable number, because it can be changed into a prime (31145221) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 254 + ... + 7896.

It is an arithmetic number, because the mean of its divisors is an integer number (3238508).

Almost surely, 2^31145225 is an apocalyptic number.

It is an amenable number.

31145225 is a deficient number, since it is larger than the sum of its proper divisors (7716871).

31145225 is a wasteful number, since it uses less digits than its factorization.

31145225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7816 (or 7811 counting only the distinct ones).

The product of its digits is 1200, while the sum is 23.

The square root of 31145225 is about 5580.7907145852. The cubic root of 31145225 is about 314.6278463782.

Adding to 31145225 its reverse (52254113), we get a palindrome (83399338).

The spelling of 31145225 in words is "thirty-one million, one hundred forty-five thousand, two hundred twenty-five".