20021009923 has 2 divisors, whose sum is σ = 20021009924. Its totient is φ = 20021009922.

The previous prime is 20021009917. The next prime is 20021009999. The reversal of 20021009923 is 32990012002.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20021009923 - 2²⁵ = 19987455491 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20021009891 and 20021009900.

It is not a weakly prime, because it can be changed into another prime (20025009923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10010504961 + 10010504962.

It is an arithmetic number, because the mean of its divisors is an integer number (10010504962).

Almost surely, 2^20021009923 is an apocalyptic number.

20021009923 is a deficient number, since it is larger than the sum of its proper divisors (1).

20021009923 is an equidigital number, since it uses as much as digits as its factorization.

20021009923 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1944, while the sum is 28.

The spelling of 20021009923 in words is "twenty billion, twenty-one million, nine thousand, nine hundred twenty-three".