7855891 has 2 divisors, whose sum is σ = 7855892. Its totient is φ = 7855890.

The previous prime is 7855871. The next prime is 7855907. The reversal of 7855891 is 1985587.

7855891 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is an emirp because it is prime and its reverse (1985587) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7855891 - 2¹³ = 7847699 is a prime.

7855891 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (7855871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3927945 + 3927946.

It is an arithmetic number, because the mean of its divisors is an integer number (3927946).

Almost surely, 2^7855891 is an apocalyptic number.

7855891 is a deficient number, since it is larger than the sum of its proper divisors (1).

7855891 is an equidigital number, since it uses as much as digits as its factorization.

7855891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 100800, while the sum is 43.

The square root of 7855891 is about 2802.8362420948. The cubic root of 7855891 is about 198.7918077207.

The spelling of 7855891 in words is "seven million, eight hundred fifty-five thousand, eight hundred ninety-one".