31321616 has 20 divisors (see below), whose sum is σ = 64255932. Its totient is φ = 14739456.

The previous prime is 31321613. The next prime is 31321637. The reversal of 31321616 is 61612313.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 24010000 + 7311616 = 4900^2 + 2704^2 .

It is a junction number, because it is equal to n+sod(n) for n = 31321591 and 31321600.

It is not an unprimeable number, because it can be changed into a prime (31321613) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 57305 + ... + 57848.

Almost surely, 2^31321616 is an apocalyptic number.

It is an amenable number.

31321616 is an abundant number, since it is smaller than the sum of its proper divisors (32934316).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31321616 is a wasteful number, since it uses less digits than its factorization.

31321616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115178 (or 115172 counting only the distinct ones).

The product of its digits is 648, while the sum is 23.

The square root of 31321616 is about 5596.5718078124. The cubic root of 31321616 is about 315.2206935833.

Adding to 31321616 its reverse (61612313), we get a palindrome (92933929).

The spelling of 31321616 in words is "thirty-one million, three hundred twenty-one thousand, six hundred sixteen".