20655707161 has 4 divisors (see below), whose sum is σ = 20667795300. Its totient is φ = 20643619024.

The previous prime is 20655707153. The next prime is 20655707173. The reversal of 20655707161 is 16170755602.

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 10911055936 + 9744651225 = 104456^2 + 98715^2 .

It is a cyclic number.

It is not a de Polignac number, because 20655707161 - 2³ = 20655707153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20655707141) 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, 6041506 + ... + 6044923.

It is an arithmetic number, because the mean of its divisors is an integer number (5166948825).

Almost surely, 2^20655707161 is an apocalyptic number.

It is an amenable number.

20655707161 is a deficient number, since it is larger than the sum of its proper divisors (12088139).

20655707161 is a wasteful number, since it uses less digits than its factorization.

20655707161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12088138.

The product of its (nonzero) digits is 88200, while the sum is 40.

The spelling of 20655707161 in words is "twenty billion, six hundred fifty-five million, seven hundred seven thousand, one hundred sixty-one".