721992 has 32 divisors (see below), whose sum is σ = 1836000. Its totient is φ = 236544.

The previous prime is 721991. The next prime is 721997. The reversal of 721992 is 299127.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (721991) 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, 1384 + ... + 1832.

It is an arithmetic number, because the mean of its divisors is an integer number (57375).

2⁷²¹⁹⁹² is an apocalyptic number.

It is an amenable number.

721992 is an abundant number, since it is smaller than the sum of its proper divisors (1114008).

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

721992 is a wasteful number, since it uses less digits than its factorization.

721992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 525 (or 521 counting only the distinct ones).

The product of its digits is 2268, while the sum is 30.

The square root of 721992 is about 849.7011239253. The cubic root of 721992 is about 89.7106758408.

The spelling of 721992 in words is "seven hundred twenty-one thousand, nine hundred ninety-two".