20766734021 has 12 divisors (see below), whose sum is σ = 22863563436. Its totient is φ = 18847984320.

The previous prime is 20766733969. The next prime is 20766734039. The reversal of 20766734021 is 12043766702.

It can be written as a sum of positive squares in 2 ways, for example, as 4341492100 + 16425241921 = 65890^2 + 128161^2 .

It is a de Polignac number, because none of the positive numbers 2^k-20766734021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20766730021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 65816 + ... + 214161.

It is an arithmetic number, because the mean of its divisors is an integer number (1905296953).

Almost surely, 2^20766734021 is an apocalyptic number.

It is an amenable number.

20766734021 is a deficient number, since it is larger than the sum of its proper divisors (2096829415).

20766734021 is a wasteful number, since it uses less digits than its factorization.

20766734021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280612 (or 280601 counting only the distinct ones).

The product of its (nonzero) digits is 84672, while the sum is 38.

The spelling of 20766734021 in words is "twenty billion, seven hundred sixty-six million, seven hundred thirty-four thousand, twenty-one".