20912839261 has 2 divisors, whose sum is σ = 20912839262. Its totient is φ = 20912839260.

The previous prime is 20912839229. The next prime is 20912839303. The reversal of 20912839261 is 16293821902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18888379225 + 2024460036 = 137435^2 + 44994^2 .

It is a cyclic number.

It is not a de Polignac number, because 20912839261 - 2⁵ = 20912839229 is a prime.

It is a super-2 number, since 2×20912839261² (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 (20912809261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10456419630 + 10456419631.

It is an arithmetic number, because the mean of its divisors is an integer number (10456419631).

Almost surely, 2^20912839261 is an apocalyptic number.

It is an amenable number.

20912839261 is a deficient number, since it is larger than the sum of its proper divisors (1).

20912839261 is an equidigital number, since it uses as much as digits as its factorization.

20912839261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 93312, while the sum is 43.

The spelling of 20912839261 in words is "twenty billion, nine hundred twelve million, eight hundred thirty-nine thousand, two hundred sixty-one".