20366722661 has 4 divisors (see below), whose sum is σ = 20576688972. Its totient is φ = 20156756352.

The previous prime is 20366722601. The next prime is 20366722667. The reversal of 20366722661 is 16622766302.

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 5572622500 + 14794100161 = 74650^2 + 121631^2 .

It is a cyclic number.

It is not a de Polignac number, because 20366722661 - 2³⁴ = 3186853477 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 (20366722667) 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, 104983010 + ... + 104983203.

It is an arithmetic number, because the mean of its divisors is an integer number (5144172243).

Almost surely, 2^20366722661 is an apocalyptic number.

It is an amenable number.

20366722661 is a deficient number, since it is larger than the sum of its proper divisors (209966311).

20366722661 is an equidigital number, since it uses as much as digits as its factorization.

20366722661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 209966310.

The product of its (nonzero) digits is 217728, while the sum is 41.

The spelling of 20366722661 in words is "twenty billion, three hundred sixty-six million, seven hundred twenty-two thousand, six hundred sixty-one".