2021121999 has 12 divisors (see below), whose sum is σ = 3143967736. Its totient is φ = 1243767312.

The previous prime is 2021121983. The next prime is 2021122001. The reversal of 2021121999 is 9991211202.

It is not a de Polignac number, because 2021121999 - 2⁴ = 2021121983 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2021126999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8637157 + ... + 8637390.

Almost surely, 2^2021121999 is an apocalyptic number.

2021121999 is a deficient number, since it is larger than the sum of its proper divisors (1122845737).

2021121999 is a wasteful number, since it uses less digits than its factorization.

2021121999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17274566 (or 17274563 counting only the distinct ones).

The product of its (nonzero) digits is 5832, while the sum is 36.

The square root of 2021121999 is about 44956.8904507418. The cubic root of 2021121999 is about 1264.3408688432.

The spelling of 2021121999 in words is "two billion, twenty-one million, one hundred twenty-one thousand, nine hundred ninety-nine".