31528225 has 9 divisors (see below), whose sum is σ = 39129843. Its totient is φ = 25200120.

The previous prime is 31528213. The next prime is 31528229. The reversal of 31528225 is 52282513.

The square root of 31528225 is 5615.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 11350161 + 20178064 = 3369^2 + 4492^2 .

It is not a de Polignac number, because 31528225 - 2²³ = 23139617 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31528193 and 31528202.

It is not an unprimeable number, because it can be changed into a prime (31528229) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 27514 + ... + 28636.

Almost surely, 2^31528225 is an apocalyptic number.

31528225 is the 5615-th square number.

31528225 is the 2808-th centered octagonal number.

It is an amenable number.

31528225 is a deficient number, since it is larger than the sum of its proper divisors (7601618).

31528225 is an frugal number, since it uses more digits than its factorization.

31528225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2256 (or 1128 counting only the distinct ones).

The product of its digits is 4800, while the sum is 28.

The cubic root of 31528225 is about 315.9122793686.

The spelling of 31528225 in words is "thirty-one million, five hundred twenty-eight thousand, two hundred twenty-five".