31635664561 has 4 divisors (see below), whose sum is σ = 31655182324. Its totient is φ = 31616146800.

The previous prime is 31635664513. The next prime is 31635664597. The reversal of 31635664561 is 16546653613.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14308944400 + 17326720161 = 119620^2 + 131631^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31635664561 is a prime.

It is a super-2 number, since 2×31635664561² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31635665561) 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, 9756450 + ... + 9759691.

It is an arithmetic number, because the mean of its divisors is an integer number (7913795581).

Almost surely, 2^31635664561 is an apocalyptic number.

It is an amenable number.

31635664561 is a deficient number, since it is larger than the sum of its proper divisors (19517763).

31635664561 is a wasteful number, since it uses less digits than its factorization.

31635664561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19517762.

The product of its digits is 1166400, while the sum is 46.

The spelling of 31635664561 in words is "thirty-one billion, six hundred thirty-five million, six hundred sixty-four thousand, five hundred sixty-one".