718991 has 8 divisors (see below), whose sum is σ = 885024. Its totient is φ = 568800.

The previous prime is 718973. The next prime is 718999. The reversal of 718991 is 199817.

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 718991 - 2¹⁰ = 717967 is a prime.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 718991.

It is not an unprimeable number, because it can be changed into a prime (718999) 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, 3860 + ... + 4041.

It is an arithmetic number, because the mean of its divisors is an integer number (110628).

2⁷¹⁸⁹⁹¹ is an apocalyptic number.

718991 is a deficient number, since it is larger than the sum of its proper divisors (166033).

718991 is a wasteful number, since it uses less digits than its factorization.

718991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7921.

The product of its digits is 4536, while the sum is 35.

The square root of 718991 is about 847.9333700238. The cubic root of 718991 is about 89.5862074194.

The spelling of 718991 in words is "seven hundred eighteen thousand, nine hundred ninety-one".