7918991 has 8 divisors (see below), whose sum is σ = 8826480. Its totient is φ = 7060608.

The previous prime is 7918987. The next prime is 7919003. The reversal of 7918991 is 1998197.

7918991 is nontrivially palindromic in base 2.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 7918991 - 2² = 7918987 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 (7918951) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11936 + ... + 12581.

It is an arithmetic number, because the mean of its divisors is an integer number (1103310).

Almost surely, 2^7918991 is an apocalyptic number.

7918991 is a deficient number, since it is larger than the sum of its proper divisors (907489).

7918991 is a wasteful number, since it uses less digits than its factorization.

7918991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24553.

The product of its digits is 40824, while the sum is 44.

The square root of 7918991 is about 2814.0701839151. The cubic root of 7918991 is about 199.3226334628.

The spelling of 7918991 in words is "seven million, nine hundred eighteen thousand, nine hundred ninety-one".