20645818771 has 8 divisors (see below), whose sum is σ = 20707552800. Its totient is φ = 20584155648.

The previous prime is 20645818723. The next prime is 20645818799. The reversal of 20645818771 is 17781854602.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20645818771 - 2⁷ = 20645818643 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20645810771) 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 in 7 ways as a sum of consecutive naturals, for example, 596965 + ... + 630601.

It is an arithmetic number, because the mean of its divisors is an integer number (2588444100).

Almost surely, 2^20645818771 is an apocalyptic number.

20645818771 is a deficient number, since it is larger than the sum of its proper divisors (61734029).

20645818771 is a wasteful number, since it uses less digits than its factorization.

20645818771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35453.

The product of its (nonzero) digits is 752640, while the sum is 49.

The spelling of 20645818771 in words is "twenty billion, six hundred forty-five million, eight hundred eighteen thousand, seven hundred seventy-one".