31613561 has 8 divisors (see below), whose sum is σ = 36503040. Its totient is φ = 26817408.

The previous prime is 31613551. The next prime is 31613579. The reversal of 31613561 is 16531613.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 31613561 - 2¹⁴ = 31597177 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 31613561.

It is not an unprimeable number, because it can be changed into a prime (31613551) 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 in 7 ways as a sum of consecutive naturals, for example, 22601 + ... + 23958.

It is an arithmetic number, because the mean of its divisors is an integer number (4562880).

Almost surely, 2^31613561 is an apocalyptic number.

It is an amenable number.

31613561 is a deficient number, since it is larger than the sum of its proper divisors (4889479).

31613561 is an equidigital number, since it uses as much as digits as its factorization.

31613561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46663.

The product of its digits is 1620, while the sum is 26.

The square root of 31613561 is about 5622.5937964608. The cubic root of 31613561 is about 316.1970443600.

The spelling of 31613561 in words is "thirty-one million, six hundred thirteen thousand, five hundred sixty-one".