7678991 has 4 divisors (see below), whose sum is σ = 7704312. Its totient is φ = 7653672.

The previous prime is 7678967. The next prime is 7678999. The reversal of 7678991 is 1998767.

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 7678991 - 2⁶ = 7678927 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7678999) 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, 12200 + ... + 12813.

It is an arithmetic number, because the mean of its divisors is an integer number (1926078).

Almost surely, 2^7678991 is an apocalyptic number.

7678991 is a deficient number, since it is larger than the sum of its proper divisors (25321).

7678991 is a wasteful number, since it uses less digits than its factorization.

7678991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25320.

The product of its digits is 190512, while the sum is 47.

The square root of 7678991 is about 2771.0992403738. The cubic root of 7678991 is about 197.2883252625.

The spelling of 7678991 in words is "seven million, six hundred seventy-eight thousand, nine hundred ninety-one".