20642407771 has 2 divisors, whose sum is σ = 20642407772. Its totient is φ = 20642407770.

The previous prime is 20642407769. The next prime is 20642407787. The reversal of 20642407771 is 17770424602.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20642407771 - 2¹ = 20642407769 is a prime.

It is a super-2 number, since 2×20642407771² (a number of 21 digits) contains 22 as substring.

Together with 20642407769, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20642407741) 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, 10321203885 + 10321203886.

It is an arithmetic number, because the mean of its divisors is an integer number (10321203886).

Almost surely, 2^20642407771 is an apocalyptic number.

20642407771 is a deficient number, since it is larger than the sum of its proper divisors (1).

20642407771 is an equidigital number, since it uses as much as digits as its factorization.

20642407771 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 131712, while the sum is 40.

The spelling of 20642407771 in words is "twenty billion, six hundred forty-two million, four hundred seven thousand, seven hundred seventy-one".