721973 has 8 divisors (see below), whose sum is σ = 873792. Its totient is φ = 582336.

The previous prime is 721961. The next prime is 721979. The reversal of 721973 is 379127.

It is a happy number.

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 721973 - 2⁶ = 721909 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 (721979) 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, 2915 + ... + 3152.

It is an arithmetic number, because the mean of its divisors is an integer number (109224).

2⁷²¹⁹⁷³ is an apocalyptic number.

It is an amenable number.

721973 is a deficient number, since it is larger than the sum of its proper divisors (151819).

721973 is a wasteful number, since it uses less digits than its factorization.

721973 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6091.

The product of its digits is 2646, while the sum is 29.

The square root of 721973 is about 849.6899434500. The cubic root of 721973 is about 89.7098888895.

The spelling of 721973 in words is "seven hundred twenty-one thousand, nine hundred seventy-three".