721900 has 18 divisors (see below), whose sum is σ = 1566740. Its totient is φ = 288720.

The previous prime is 721891. The next prime is 721909. The reversal of 721900 is 9127.

721900 is nontrivially palindromic in base 9.

721900 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (721891) and next prime (721909).

It is a super-2 number, since 2×721900² = 1042279220000, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (721909) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3510 + ... + 3709.

2⁷²¹⁹⁰⁰ is an apocalyptic number.

It is an amenable number.

721900 is an abundant number, since it is smaller than the sum of its proper divisors (844840).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

721900 is a wasteful number, since it uses less digits than its factorization.

721900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7233 (or 7226 counting only the distinct ones).

The product of its (nonzero) digits is 126, while the sum is 19.

The square root of 721900 is about 849.6469855181. The cubic root of 721900 is about 89.7068652110.

The spelling of 721900 in words is "seven hundred twenty-one thousand, nine hundred".