20530579961 has 4 divisors (see below), whose sum is σ = 20790460800. Its totient is φ = 20270699124.

The previous prime is 20530579939. The next prime is 20530580003. The reversal of 20530579961 is 16997503502.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20530579961 - 2²⁶ = 20463471097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20530579931) 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, 129940301 + ... + 129940458.

It is an arithmetic number, because the mean of its divisors is an integer number (5197615200).

Almost surely, 2^20530579961 is an apocalyptic number.

It is an amenable number.

20530579961 is a deficient number, since it is larger than the sum of its proper divisors (259880839).

20530579961 is an equidigital number, since it uses as much as digits as its factorization.

20530579961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 259880838.

The product of its (nonzero) digits is 510300, while the sum is 47.

The spelling of 20530579961 in words is "twenty billion, five hundred thirty million, five hundred seventy-nine thousand, nine hundred sixty-one".