31381517225 has 6 divisors (see below), whose sum is σ = 38913081390. Its totient is φ = 25105213760.

The previous prime is 31381517221. The next prime is 31381517243. The reversal of 31381517225 is 52271518313.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 5452788649 + 25928728576 = 73843^2 + 161024^2 .

It is not a de Polignac number, because 31381517225 - 2² = 31381517221 is a prime.

It is not an unprimeable number, because it can be changed into a prime (31381517221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 627630320 + ... + 627630369.

It is an arithmetic number, because the mean of its divisors is an integer number (6485513565).

Almost surely, 2^31381517225 is an apocalyptic number.

It is an amenable number.

31381517225 is a deficient number, since it is larger than the sum of its proper divisors (7531564165).

31381517225 is a wasteful number, since it uses less digits than its factorization.

31381517225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1255260699 (or 1255260694 counting only the distinct ones).

The product of its digits is 50400, while the sum is 38.

The spelling of 31381517225 in words is "thirty-one billion, three hundred eighty-one million, five hundred seventeen thousand, two hundred twenty-five".