20858732761 has 2 divisors, whose sum is σ = 20858732762. Its totient is φ = 20858732760.

The previous prime is 20858732759. The next prime is 20858732809. The reversal of 20858732761 is 16723785802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17882375625 + 2976357136 = 133725^2 + 54556^2 .

It is a cyclic number.

It is not a de Polignac number, because 20858732761 - 2¹ = 20858732759 is a prime.

Together with 20858732759, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20858732711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10429366380 + 10429366381.

It is an arithmetic number, because the mean of its divisors is an integer number (10429366381).

Almost surely, 2^20858732761 is an apocalyptic number.

It is an amenable number.

20858732761 is a deficient number, since it is larger than the sum of its proper divisors (1).

20858732761 is an equidigital number, since it uses as much as digits as its factorization.

20858732761 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1128960, while the sum is 49.

The spelling of 20858732761 in words is "twenty billion, eight hundred fifty-eight million, seven hundred thirty-two thousand, seven hundred sixty-one".