31121716 has 6 divisors (see below), whose sum is σ = 54463010. Its totient is φ = 15560856.

The previous prime is 31121711. The next prime is 31121719. The reversal of 31121716 is 61712113.

It can be written as a sum of positive squares in only one way, i.e., 27081616 + 4040100 = 5204^2 + 2010^2 .

It is a super-2 number, since 2×31121716² = 1937122413569312, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31121711) 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 as a sum of consecutive naturals, namely, 3890211 + ... + 3890218.

Almost surely, 2^31121716 is an apocalyptic number.

It is an amenable number.

31121716 is a deficient number, since it is larger than the sum of its proper divisors (23341294).

31121716 is a wasteful number, since it uses less digits than its factorization.

31121716 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7780433 (or 7780431 counting only the distinct ones).

The product of its digits is 252, while the sum is 22.

The square root of 31121716 is about 5578.6840742240. The cubic root of 31121716 is about 314.5486641189.

Adding to 31121716 its reverse (61712113), we get a palindrome (92833829).

The spelling of 31121716 in words is "thirty-one million, one hundred twenty-one thousand, seven hundred sixteen".