2121979868 has 12 divisors (see below), whose sum is σ = 3783530520. Its totient is φ = 1040971152.

The previous prime is 2121979843. The next prime is 2121979889. The reversal of 2121979868 is 8689791212.

It is a Harshad number since it is a multiple of its sum of digits (53).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5004458 + ... + 5004881.

It is an arithmetic number, because the mean of its divisors is an integer number (315294210).

Almost surely, 2^2121979868 is an apocalyptic number.

It is an amenable number.

2121979868 is a deficient number, since it is larger than the sum of its proper divisors (1661550652).

2121979868 is a wasteful number, since it uses less digits than its factorization.

2121979868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10009396 (or 10009394 counting only the distinct ones).

The product of its digits is 870912, while the sum is 53.

The square root of 2121979868 is about 46064.9527081055. The cubic root of 2121979868 is about 1285.0314391214.

The spelling of 2121979868 in words is "two billion, one hundred twenty-one million, nine hundred seventy-nine thousand, eight hundred sixty-eight".