31661613 has 6 divisors (see below), whose sum is σ = 45733454. Its totient is φ = 21107736.

The previous prime is 31661611. The next prime is 31661681. The reversal of 31661613 is 31616613.

It is a happy number.

31661613 is a `hidden beast` number, since 31 + 6 + 616 + 13 = 666.

It can be written as a sum of positive squares in only one way, i.e., 28323684 + 3337929 = 5322^2 + 1827^2 .

It is not a de Polignac number, because 31661613 - 2¹ = 31661611 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31661611) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1758970 + ... + 1758987.

Almost surely, 2^31661613 is an apocalyptic number.

It is an amenable number.

31661613 is a deficient number, since it is larger than the sum of its proper divisors (14071841).

31661613 is a wasteful number, since it uses less digits than its factorization.

31661613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3517963 (or 3517960 counting only the distinct ones).

The product of its digits is 1944, while the sum is 27.

The square root of 31661613 is about 5626.8652907280. The cubic root of 31661613 is about 316.3571677190.

The spelling of 31661613 in words is "thirty-one million, six hundred sixty-one thousand, six hundred thirteen".