20355053661 has 6 divisors (see below), whose sum is σ = 29401744190. Its totient is φ = 13570035768.

The previous prime is 20355053639. The next prime is 20355053669. The reversal of 20355053661 is 16635055302.

It can be written as a sum of positive squares in only one way, i.e., 20112628761 + 242424900 = 141819^2 + 15570^2 .

It is not a de Polignac number, because 20355053661 - 2¹⁰ = 20355052637 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 (20355053669) 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, 1130836306 + ... + 1130836323.

Almost surely, 2^20355053661 is an apocalyptic number.

It is an amenable number.

20355053661 is a deficient number, since it is larger than the sum of its proper divisors (9046690529).

20355053661 is a wasteful number, since it uses less digits than its factorization.

20355053661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2261672635 (or 2261672632 counting only the distinct ones).

The product of its (nonzero) digits is 81000, while the sum is 36.

The spelling of 20355053661 in words is "twenty billion, three hundred fifty-five million, fifty-three thousand, six hundred sixty-one".