31225145 has 32 divisors (see below), whose sum is σ = 45342720. Its totient is φ = 20180160.

The previous prime is 31225133. The next prime is 31225147. The reversal of 31225145 is 54152213.

31225145 = 60² + 61² + ... + 454².

It is not a de Polignac number, because 31225145 - 2⁶ = 31225081 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a self number, because there is not a number n which added to its sum of digits gives 31225145.

It is not an unprimeable number, because it can be changed into a prime (31225147) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 63350 + ... + 63840.

It is an arithmetic number, because the mean of its divisors is an integer number (1416960).

Almost surely, 2^31225145 is an apocalyptic number.

31225145 is a gapful number since it is divisible by the number (35) formed by its first and last digit.

It is an amenable number.

31225145 is a deficient number, since it is larger than the sum of its proper divisors (14117575).

31225145 is a wasteful number, since it uses less digits than its factorization.

31225145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 605.

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

The square root of 31225145 is about 5587.9464027494. The cubic root of 31225145 is about 314.8967327572.

Adding to 31225145 its reverse (54152213), we get a palindrome (85377358).

The spelling of 31225145 in words is "thirty-one million, two hundred twenty-five thousand, one hundred forty-five".