2121668787 has 48 divisors (see below), whose sum is σ = 3453795072. Its totient is φ = 1152930240.

The previous prime is 2121668743. The next prime is 2121668807. The reversal of 2121668787 is 7878661212.

It is not a de Polignac number, because 2121668787 - 2⁸ = 2121668531 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2121668707) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 610228 + ... + 613694.

It is an arithmetic number, because the mean of its divisors is an integer number (71954064).

Almost surely, 2^2121668787 is an apocalyptic number.

2121668787 is a deficient number, since it is larger than the sum of its proper divisors (1332126285).

2121668787 is a wasteful number, since it uses less digits than its factorization.

2121668787 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3688 (or 3681 counting only the distinct ones).

The product of its digits is 451584, while the sum is 48.

The square root of 2121668787 is about 46061.5760368661. The cubic root of 2121668787 is about 1284.9686411016.

The spelling of 2121668787 in words is "two billion, one hundred twenty-one million, six hundred sixty-eight thousand, seven hundred eighty-seven".