7971791 has 4 divisors (see below), whose sum is σ = 8009784. Its totient is φ = 7933800.

The previous prime is 7971787. The next prime is 7971833. The reversal of 7971791 is 1971797.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1971797 = 29 ⋅67993.

It is a cyclic number.

It is not a de Polignac number, because 7971791 - 2² = 7971787 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7971701) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18680 + ... + 19101.

It is an arithmetic number, because the mean of its divisors is an integer number (2002446).

Almost surely, 2^7971791 is an apocalyptic number.

7971791 is a deficient number, since it is larger than the sum of its proper divisors (37993).

7971791 is a wasteful number, since it uses less digits than its factorization.

7971791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37992.

The product of its digits is 27783, while the sum is 41.

The square root of 7971791 is about 2823.4360272547. The cubic root of 7971791 is about 199.7646481562.

The spelling of 7971791 in words is "seven million, nine hundred seventy-one thousand, seven hundred ninety-one".