20929667021 has 4 divisors (see below), whose sum is σ = 21284407200. Its totient is φ = 20574926844.

The previous prime is 20929666993. The next prime is 20929667027. The reversal of 20929667021 is 12076692902.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20929667021 - 2¹⁸ = 20929404877 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 (20929667027) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 177370001 + ... + 177370118.

It is an arithmetic number, because the mean of its divisors is an integer number (5321101800).

Almost surely, 2^20929667021 is an apocalyptic number.

It is an amenable number.

20929667021 is a deficient number, since it is larger than the sum of its proper divisors (354740179).

20929667021 is an equidigital number, since it uses as much as digits as its factorization.

20929667021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 354740178.

The product of its (nonzero) digits is 163296, while the sum is 44.

The spelling of 20929667021 in words is "twenty billion, nine hundred twenty-nine million, six hundred sixty-seven thousand, twenty-one".