721072 has 40 divisors (see below), whose sum is σ = 1620432. Its totient is φ = 307200.

The previous prime is 721057. The next prime is 721079. The reversal of 721072 is 270127.

It is a hoax number, since the sum of its digits (19) coincides with the sum of the digits of its distinct prime factors.

It is an alternating number because its digits alternate between odd and even.

It is not an unprimeable number, because it can be changed into a prime (721079) by changing a digit.

721072 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2872 + ... + 3112.

2⁷²¹⁰⁷² is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 721072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (810216).

721072 is an abundant number, since it is smaller than the sum of its proper divisors (899360).

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

721072 is a wasteful number, since it uses less digits than its factorization.

721072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 277 (or 271 counting only the distinct ones).

The product of its (nonzero) digits is 196, while the sum is 19.

The square root of 721072 is about 849.1595845305. The cubic root of 721072 is about 89.6725549646.

Adding to 721072 its reverse (270127), we get a palindrome (991199).

The spelling of 721072 in words is "seven hundred twenty-one thousand, seventy-two", and thus it is an iban number.