31621225 has 12 divisors (see below), whose sum is σ = 41274640. Its totient is φ = 23965200.

The previous prime is 31621217. The next prime is 31621229. The reversal of 31621225 is 52212613.

It is not a de Polignac number, because 31621225 - 2³ = 31621217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31621196 and 31621205.

It is not an unprimeable number, because it can be changed into a prime (31621229) 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, 32811 + ... + 33760.

Almost surely, 2^31621225 is an apocalyptic number.

It is an amenable number.

31621225 is a deficient number, since it is larger than the sum of its proper divisors (9653415).

31621225 is a wasteful number, since it uses less digits than its factorization.

31621225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66600 (or 66595 counting only the distinct ones).

The product of its digits is 720, while the sum is 22.

The square root of 31621225 is about 5623.2752911448. The cubic root of 31621225 is about 316.2225939266. Note that the first 3 decimals are identical.

Adding to 31621225 its reverse (52212613), we get a palindrome (83833838).

The spelling of 31621225 in words is "thirty-one million, six hundred twenty-one thousand, two hundred twenty-five".