20021099 has 4 divisors (see below), whose sum is σ = 22881264. Its totient is φ = 17160936.

The previous prime is 20021093. The next prime is 20021137. The reversal of 20021099 is 99012002.

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 20021099 - 2²⁴ = 3243883 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20021093) 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, 1430072 + ... + 1430085.

It is an arithmetic number, because the mean of its divisors is an integer number (5720316).

Almost surely, 2^20021099 is an apocalyptic number.

20021099 is a deficient number, since it is larger than the sum of its proper divisors (2860165).

20021099 is an equidigital number, since it uses as much as digits as its factorization.

20021099 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2860164.

The product of its (nonzero) digits is 324, while the sum is 23.

The square root of 20021099 is about 4474.4942730995. The cubic root of 20021099 is about 271.5371806088.

The spelling of 20021099 in words is "twenty million, twenty-one thousand, ninety-nine".