6791816565921 has 8 divisors (see below), whose sum is σ = 9055780733664. Its totient is φ = 4527865054400.

The previous prime is 6791816565899. The next prime is 6791816565997. The reversal of 6791816565921 is 1295656181976.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 6791816565921 - 2¹⁷ = 6791816434849 is a prime.

It is a super-2 number, since 2×6791816565921² (a number of 26 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (6791816561921) 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, 1831755 + ... + 4115696.

It is an arithmetic number, because the mean of its divisors is an integer number (1131972591708).

Almost surely, 2^{6791816565921} is an apocalyptic number.

It is an amenable number.

6791816565921 is a deficient number, since it is larger than the sum of its proper divisors (2263964167743).

6791816565921 is a wasteful number, since it uses less digits than its factorization.

6791816565921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6328111.

The product of its digits is 48988800, while the sum is 66.

The spelling of 6791816565921 in words is "six trillion, seven hundred ninety-one billion, eight hundred sixteen million, five hundred sixty-five thousand, nine hundred twenty-one".