7856491 has 4 divisors (see below), whose sum is σ = 7872984. Its totient is φ = 7840000.

The previous prime is 7856483. The next prime is 7856503. The reversal of 7856491 is 1946587.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1946587 = 59 ⋅32993.

It is a cyclic number.

It is not a de Polignac number, because 7856491 - 2³ = 7856483 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 (7856411) 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, 7510 + ... + 8491.

It is an arithmetic number, because the mean of its divisors is an integer number (1968246).

Almost surely, 2^7856491 is an apocalyptic number.

7856491 is a deficient number, since it is larger than the sum of its proper divisors (16493).

7856491 is a wasteful number, since it uses less digits than its factorization.

7856491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16492.

The product of its digits is 60480, while the sum is 40.

The square root of 7856491 is about 2802.9432744884. The cubic root of 7856491 is about 198.7968685533.

It can be divided in two parts, 7856 and 491, that multiplied together give a square (3857296 = 1964²).

The spelling of 7856491 in words is "seven million, eight hundred fifty-six thousand, four hundred ninety-one".