20847639269 has 2 divisors, whose sum is σ = 20847639270. Its totient is φ = 20847639268.

The previous prime is 20847639251. The next prime is 20847639299. The reversal of 20847639269 is 96293674802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20132772100 + 714867169 = 141890^2 + 26737^2 .

It is a cyclic number.

It is not a de Polignac number, because 20847639269 - 2⁸ = 20847639013 is a prime.

It is a super-2 number, since 2×20847639269² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20847639229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10423819634 + 10423819635.

It is an arithmetic number, because the mean of its divisors is an integer number (10423819635).

Almost surely, 2^20847639269 is an apocalyptic number.

It is an amenable number.

20847639269 is a deficient number, since it is larger than the sum of its proper divisors (1).

20847639269 is an equidigital number, since it uses as much as digits as its factorization.

20847639269 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7838208, while the sum is 56.

The spelling of 20847639269 in words is "twenty billion, eight hundred forty-seven million, six hundred thirty-nine thousand, two hundred sixty-nine".