20665292971 has 2 divisors, whose sum is σ = 20665292972. Its totient is φ = 20665292970.

The previous prime is 20665292959. The next prime is 20665293037. The reversal of 20665292971 is 17929256602.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20665292971 is a prime.

It is not a weakly prime, because it can be changed into another prime (20665292071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10332646485 + 10332646486.

It is an arithmetic number, because the mean of its divisors is an integer number (10332646486).

Almost surely, 2^20665292971 is an apocalyptic number.

20665292971 is a deficient number, since it is larger than the sum of its proper divisors (1).

20665292971 is an equidigital number, since it uses as much as digits as its factorization.

20665292971 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 816480, while the sum is 49.

The spelling of 20665292971 in words is "twenty billion, six hundred sixty-five million, two hundred ninety-two thousand, nine hundred seventy-one".