721972 has 12 divisors (see below), whose sum is σ = 1271200. Its totient is φ = 358776.

The previous prime is 721961. The next prime is 721979. The reversal of 721972 is 279127.

It is a happy number.

721972 is nontrivially palindromic in base 7.

It is a self number, because there is not a number n which added to its sum of digits gives 721972.

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 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, 343 + ... + 1249.

2⁷²¹⁹⁷² is an apocalyptic number.

It is an amenable number.

721972 is a deficient number, since it is larger than the sum of its proper divisors (549228).

721972 is a wasteful number, since it uses less digits than its factorization.

721972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1110 (or 1108 counting only the distinct ones).

The product of its digits is 1764, while the sum is 28.

The square root of 721972 is about 849.6893549998. The cubic root of 721972 is about 89.7098474706.

The spelling of 721972 in words is "seven hundred twenty-one thousand, nine hundred seventy-two".