20021009999 has 2 divisors, whose sum is σ = 20021010000. Its totient is φ = 20021009998.

The previous prime is 20021009923. The next prime is 20021010029. The reversal of 20021009999 is 99990012002.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20021009999 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20021009399) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10010504999 + 10010505000.

It is an arithmetic number, because the mean of its divisors is an integer number (10010505000).

Almost surely, 2^20021009999 is an apocalyptic number.

20021009999 is a deficient number, since it is larger than the sum of its proper divisors (1).

20021009999 is an equidigital number, since it uses as much as digits as its factorization.

20021009999 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 26244, while the sum is 41.

The spelling of 20021009999 in words is "twenty billion, twenty-one million, nine thousand, nine hundred ninety-nine".