7979991 has 8 divisors (see below), whose sum is σ = 10705920. Its totient is φ = 5287032.

The previous prime is 7979969. The next prime is 7980013. The reversal of 7979991 is 1999797.

It is an interprime number because it is at equal distance from previous prime (7979969) and next prime (7980013).

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

It is not a de Polignac number, because 7979991 - 2⁷ = 7979863 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7979911) 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, 7671 + ... + 8648.

It is an arithmetic number, because the mean of its divisors is an integer number (1338240).

Almost surely, 2^7979991 is an apocalyptic number.

7979991 is a deficient number, since it is larger than the sum of its proper divisors (2725929).

7979991 is a wasteful number, since it uses less digits than its factorization.

7979991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16485.

The product of its digits is 321489, while the sum is 51.

The square root of 7979991 is about 2824.8877853819. The cubic root of 7979991 is about 199.8331191259.

The spelling of 7979991 in words is "seven million, nine hundred seventy-nine thousand, nine hundred ninety-one".