721983 has 8 divisors (see below), whose sum is σ = 979200. Its totient is φ = 473048.

The previous prime is 721979. The next prime is 721991. The reversal of 721983 is 389127.

It is a happy number.

721983 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 721983 - 2² = 721979 is a prime.

721983 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 721983.

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 721983.

It is not an unprimeable number, because it can be changed into a prime (721283) by changing a digit.

It is an upside-down number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1863 + ... + 2216.

It is an arithmetic number, because the mean of its divisors is an integer number (122400).

2⁷²¹⁹⁸³ is an apocalyptic number.

721983 is a deficient number, since it is larger than the sum of its proper divisors (257217).

721983 is a wasteful number, since it uses less digits than its factorization.

721983 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4141.

The product of its digits is 3024, while the sum is 30.

The square root of 721983 is about 849.6958279290. The cubic root of 721983 is about 89.7103030761.

The spelling of 721983 in words is "seven hundred twenty-one thousand, nine hundred eighty-three".