20405651969 has 2 divisors, whose sum is σ = 20405651970. Its totient is φ = 20405651968.

The previous prime is 20405651963. The next prime is 20405652061. The reversal of 20405651969 is 96915650402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15320250625 + 5085401344 = 123775^2 + 71312^2 .

It is a cyclic number.

It is not a de Polignac number, because 20405651969 - 2⁸ = 20405651713 is a prime.

It is a super-2 number, since 2×20405651969² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20405651963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10202825984 + 10202825985.

It is an arithmetic number, because the mean of its divisors is an integer number (10202825985).

Almost surely, 2^20405651969 is an apocalyptic number.

It is an amenable number.

20405651969 is a deficient number, since it is larger than the sum of its proper divisors (1).

20405651969 is an equidigital number, since it uses as much as digits as its factorization.

20405651969 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 583200, while the sum is 47.

The spelling of 20405651969 in words is "twenty billion, four hundred five million, six hundred fifty-one thousand, nine hundred sixty-nine".