13326620661 has 10 divisors (see below), whose sum is σ = 19907668022. Its totient is φ = 8884413720.

The previous prime is 13326620633. The next prime is 13326620663. The reversal of 13326620661 is 16602662331.

13326620661 is a `hidden beast` number, since 1 + 3 + 3 + 26 + 620 + 6 + 6 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 10278918225 + 3047702436 = 101385^2 + 55206^2 .

It is not a de Polignac number, because 13326620661 - 2¹⁵ = 13326587893 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 (13326620663) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 82263010 + ... + 82263171.

Almost surely, 2^13326620661 is an apocalyptic number.

It is an amenable number.

13326620661 is a deficient number, since it is larger than the sum of its proper divisors (6581047361).

13326620661 is an equidigital number, since it uses as much as digits as its factorization.

13326620661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164526193 (or 164526184 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 36.

The spelling of 13326620661 in words is "thirteen billion, three hundred twenty-six million, six hundred twenty thousand, six hundred sixty-one".