7991487 has 16 divisors (see below), whose sum is σ = 13530880. Its totient is φ = 4566456.

The previous prime is 7991483. The next prime is 7991531. The reversal of 7991487 is 7841997.

It is not a de Polignac number, because 7991487 - 2² = 7991483 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7991483) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20953 + ... + 21330.

It is an arithmetic number, because the mean of its divisors is an integer number (845680).

Almost surely, 2^7991487 is an apocalyptic number.

7991487 is a deficient number, since it is larger than the sum of its proper divisors (5539393).

7991487 is a wasteful number, since it uses less digits than its factorization.

7991487 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42299 (or 42293 counting only the distinct ones).

The product of its digits is 127008, while the sum is 45.

The square root of 7991487 is about 2826.9218241755. The cubic root of 7991487 is about 199.9290331548.

The spelling of 7991487 in words is "seven million, nine hundred ninety-one thousand, four hundred eighty-seven".