31315216 has 15 divisors (see below), whose sum is σ = 60716631. Its totient is φ = 15646416.

The previous prime is 31315201. The next prime is 31315231. The reversal of 31315216 is 61251313.

It is a happy number.

The square root of 31315216 is 5596.

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

It is an interprime number because it is at equal distance from previous prime (31315201) and next prime (31315231).

It is a Duffinian number.

It is an unprimeable number.

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 2 ways as a sum of consecutive naturals, for example, 21685 + ... + 23083.

Almost surely, 2^31315216 is an apocalyptic number.

31315216 is the 5596-th square number.

It is an amenable number.

31315216 is a deficient number, since it is larger than the sum of its proper divisors (29401415).

31315216 is an frugal number, since it uses more digits than its factorization.

31315216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2806 (or 1401 counting only the distinct ones).

The product of its digits is 540, while the sum is 22.

The cubic root of 31315216 is about 315.1992222575.

Adding to 31315216 its reverse (61251313), we get a palindrome (92566529).

The spelling of 31315216 in words is "thirty-one million, three hundred fifteen thousand, two hundred sixteen".