721933 has 4 divisors (see below), whose sum is σ = 724768. Its totient is φ = 719100.

The previous prime is 721921. The next prime is 721951. The reversal of 721933 is 339127.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-721933 is a prime.

It is a d-powerful number, because it can be written as 7³ + 2¹⁷ + 9⁵ + 1 + 3³ + 3¹² .

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 721898 and 721907.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721333) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 993 + ... + 1558.

It is an arithmetic number, because the mean of its divisors is an integer number (181192).

2⁷²¹⁹³³ is an apocalyptic number.

It is an amenable number.

721933 is a deficient number, since it is larger than the sum of its proper divisors (2835).

721933 is a wasteful number, since it uses less digits than its factorization.

721933 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2834.

The product of its digits is 1134, while the sum is 25.

The square root of 721933 is about 849.6664051262. Note that the first 3 decimals coincide. The cubic root of 721933 is about 89.7082321046.

The spelling of 721933 in words is "seven hundred twenty-one thousand, nine hundred thirty-three".