719991 has 6 divisors (see below), whose sum is σ = 1040000. Its totient is φ = 479988.

The previous prime is 719989. The next prime is 720007. The reversal of 719991 is 199917.

It is not a de Polignac number, because 719991 - 2¹ = 719989 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 (719911) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 39991 + ... + 40008.

2⁷¹⁹⁹⁹¹ is an apocalyptic number.

719991 is a deficient number, since it is larger than the sum of its proper divisors (320009).

719991 is a wasteful number, since it uses less digits than its factorization.

719991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80005 (or 80002 counting only the distinct ones).

The product of its digits is 5103, while the sum is 36.

The square root of 719991 is about 848.5228341064. The cubic root of 719991 is about 89.6277214792.

Adding to 719991 its sum of digits (36), we get a palindrome (720027).

The spelling of 719991 in words is "seven hundred nineteen thousand, nine hundred ninety-one".