31983561 has 6 divisors (see below), whose sum is σ = 46198490. Its totient is φ = 21322368.

The previous prime is 31983559. The next prime is 31983571. The reversal of 31983561 is 16538913.

It is a happy number.

31983561 is a `hidden beast` number, since 3 + 1 + 98 + 3 + 561 = 666.

It can be written as a sum of positive squares in only one way, i.e., 29909961 + 2073600 = 5469^2 + 1440^2 .

It is not a de Polignac number, because 31983561 - 2¹ = 31983559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31983521) 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, 1776856 + ... + 1776873.

Almost surely, 2^31983561 is an apocalyptic number.

It is an amenable number.

31983561 is a deficient number, since it is larger than the sum of its proper divisors (14214929).

31983561 is a wasteful number, since it uses less digits than its factorization.

31983561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3553735 (or 3553732 counting only the distinct ones).

The product of its digits is 19440, while the sum is 36.

The square root of 31983561 is about 5655.4010467870. The cubic root of 31983561 is about 317.4258359026.

The spelling of 31983561 in words is "thirty-one million, nine hundred eighty-three thousand, five hundred sixty-one".