31997225 has 12 divisors (see below), whose sum is σ = 42729036. Its totient is φ = 23628480.

The previous prime is 31997221. The next prime is 31997227. The reversal of 31997225 is 52279913.

It can be written as a sum of positive squares in 6 ways, for example, as 6889 + 31990336 = 83^2 + 5656^2 .

It is not a de Polignac number, because 31997225 - 2² = 31997221 is a prime.

It is a hoax number, since the sum of its digits (38) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31997221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 48902 + ... + 49551.

It is an arithmetic number, because the mean of its divisors is an integer number (3560753).

Almost surely, 2^31997225 is an apocalyptic number.

It is an amenable number.

31997225 is a deficient number, since it is larger than the sum of its proper divisors (10731811).

31997225 is a wasteful number, since it uses less digits than its factorization.

31997225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98476 (or 98471 counting only the distinct ones).

The product of its digits is 34020, while the sum is 38.

The square root of 31997225 is about 5656.6089665099. The cubic root of 31997225 is about 317.4710329660.

The spelling of 31997225 in words is "thirty-one million, nine hundred ninety-seven thousand, two hundred twenty-five".