6921999790 has 16 divisors (see below), whose sum is σ = 12461263200. Its totient is φ = 2768430240.

The previous prime is 6921999787. The next prime is 6921999797. The reversal of 6921999790 is 979991296.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6921999797) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40111 + ... + 124309.

It is an arithmetic number, because the mean of its divisors is an integer number (778828950).

Almost surely, 2^6921999790 is an apocalyptic number.

6921999790 is a deficient number, since it is larger than the sum of its proper divisors (5539263410).

6921999790 is a wasteful number, since it uses less digits than its factorization.

6921999790 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92427.

The product of its (nonzero) digits is 4960116, while the sum is 61.

The square root of 6921999790 is about 83198.5564177648. The cubic root of 6921999790 is about 1905.7994352984.

The spelling of 6921999790 in words is "six billion, nine hundred twenty-one million, nine hundred ninety-nine thousand, seven hundred ninety".