7951891 has 4 divisors (see below), whose sum is σ = 8010072. Its totient is φ = 7893712.

The previous prime is 7951849. The next prime is 7951897. The reversal of 7951891 is 1981597.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 7951891 - 2¹⁵ = 7919123 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7951897) 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, 28885 + ... + 29158.

It is an arithmetic number, because the mean of its divisors is an integer number (2002518).

Almost surely, 2^7951891 is an apocalyptic number.

7951891 is a deficient number, since it is larger than the sum of its proper divisors (58181).

7951891 is a wasteful number, since it uses less digits than its factorization.

7951891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58180.

The product of its digits is 22680, while the sum is 40.

The square root of 7951891 is about 2819.9097503289. The cubic root of 7951891 is about 199.5982853335.

The spelling of 7951891 in words is "seven million, nine hundred fifty-one thousand, eight hundred ninety-one".