20021220209999 has 4 divisors (see below), whose sum is σ = 20021368301040. Its totient is φ = 20021072118960.

The previous prime is 20021220209987. The next prime is 20021220210001. The reversal of 20021220209999 is 99990202212002.

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 20021220209999 - 2⁴ = 20021220209983 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 (20021220209929) 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, 73842542 + ... + 74113179.

It is an arithmetic number, because the mean of its divisors is an integer number (5005342075260).

Almost surely, 2^{20021220209999} is an apocalyptic number.

20021220209999 is a deficient number, since it is larger than the sum of its proper divisors (148091041).

20021220209999 is a wasteful number, since it uses less digits than its factorization.

20021220209999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148091040.

The product of its (nonzero) digits is 209952, while the sum is 47.

The spelling of 20021220209999 in words is "twenty trillion, twenty-one billion, two hundred twenty million, two hundred nine thousand, nine hundred ninety-nine".