2021987989 has 24 divisors (see below), whose sum is σ = 2453192448. Its totient is φ = 1659813120.

The previous prime is 2021987963. The next prime is 2021988043. The reversal of 2021987989 is 9897891202.

It is not a de Polignac number, because 2021987989 - 2⁷ = 2021987861 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2021987389) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 140482 + ... + 154204.

It is an arithmetic number, because the mean of its divisors is an integer number (102216352).

Almost surely, 2^2021987989 is an apocalyptic number.

It is an amenable number.

2021987989 is a deficient number, since it is larger than the sum of its proper divisors (431204459).

2021987989 is a wasteful number, since it uses less digits than its factorization.

2021987989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13865 (or 13858 counting only the distinct ones).

The product of its (nonzero) digits is 1306368, while the sum is 55.

The square root of 2021987989 is about 44966.5207571144. The cubic root of 2021987989 is about 1264.5214204063.

The spelling of 2021987989 in words is "two billion, twenty-one million, nine hundred eighty-seven thousand, nine hundred eighty-nine".