20021111999 has 4 divisors (see below), whose sum is σ = 22881270864. Its totient is φ = 17160953136.

The previous prime is 20021111969. The next prime is 20021112053. The reversal of 20021111999 is 99911112002.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20021111999 - 2²⁴ = 20004334783 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 (20021111909) 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, 1430079422 + ... + 1430079435.

It is an arithmetic number, because the mean of its divisors is an integer number (5720317716).

Almost surely, 2^20021111999 is an apocalyptic number.

20021111999 is a deficient number, since it is larger than the sum of its proper divisors (2860158865).

20021111999 is an equidigital number, since it uses as much as digits as its factorization.

20021111999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2860158864.

The product of its (nonzero) digits is 2916, while the sum is 35.

The spelling of 20021111999 in words is "twenty billion, twenty-one million, one hundred eleven thousand, nine hundred ninety-nine".