7854991 has 2 divisors, whose sum is σ = 7854992. Its totient is φ = 7854990.

The previous prime is 7854967. The next prime is 7855009. The reversal of 7854991 is 1994587.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 7854991 - 2⁷ = 7854863 is a prime.

It is a super-2 number, since 2×7854991² = 123401767220162, which contains 22 as substring.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7834991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3927495 + 3927496.

It is an arithmetic number, because the mean of its divisors is an integer number (3927496).

Almost surely, 2^7854991 is an apocalyptic number.

7854991 is a deficient number, since it is larger than the sum of its proper divisors (1).

7854991 is an equidigital number, since it uses as much as digits as its factorization.

7854991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 90720, while the sum is 43.

The square root of 7854991 is about 2802.6756858402. The cubic root of 7854991 is about 198.7842159886.

It can be divided in two parts, 785 and 4991, that added together give a square (5776 = 76²).

The spelling of 7854991 in words is "seven million, eight hundred fifty-four thousand, nine hundred ninety-one".