722991 has 4 divisors (see below), whose sum is σ = 963992. Its totient is φ = 481992.

The previous prime is 722983. The next prime is 723029. The reversal of 722991 is 199227.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 722991 - 2³ = 722983 is a prime.

It is a D-number.

It is a Duffinian number.

722991 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (722921) 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, 120496 + ... + 120501.

It is an arithmetic number, because the mean of its divisors is an integer number (240998).

2⁷²²⁹⁹¹ is an apocalyptic number.

722991 is a deficient number, since it is larger than the sum of its proper divisors (241001).

722991 is a wasteful number, since it uses less digits than its factorization.

722991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 241000.

The product of its digits is 2268, while the sum is 30.

The square root of 722991 is about 850.2887744761. The cubic root of 722991 is about 89.7520334836.

The spelling of 722991 in words is "seven hundred twenty-two thousand, nine hundred ninety-one".