7816991 has 32 divisors (see below), whose sum is σ = 10579968. Its totient is φ = 5598720.

The previous prime is 7816981. The next prime is 7816997. The reversal of 7816991 is 1996187.

It is a happy number.

7816991 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 7816991 - 2¹⁸ = 7554847 is a prime.

It is a super-2 number, since 2×7816991² = 122210696588162, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7816997) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 47876 + ... + 48038.

It is an arithmetic number, because the mean of its divisors is an integer number (330624).

Almost surely, 2^7816991 is an apocalyptic number.

7816991 is a deficient number, since it is larger than the sum of its proper divisors (2762977).

7816991 is a wasteful number, since it uses less digits than its factorization.

7816991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 231.

The product of its digits is 27216, while the sum is 41.

The square root of 7816991 is about 2795.8882309563. Note that the first 3 decimals coincide. The cubic root of 7816991 is about 198.4631456428.

The spelling of 7816991 in words is "seven million, eight hundred sixteen thousand, nine hundred ninety-one".