721972224 has 88 divisors (see below), whose sum is σ = 2138214320. Its totient is φ = 240648192.

The previous prime is 721972213. The next prime is 721972247. The reversal of 721972224 is 422279127.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14592 + ... + 40704.

It is an arithmetic number, because the mean of its divisors is an integer number (24297890).

Almost surely, 2^721972224 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 721972224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1069107160).

721972224 is an abundant number, since it is smaller than the sum of its proper divisors (1416242096).

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

721972224 is a wasteful number, since it uses less digits than its factorization.

721972224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26142 (or 26118 counting only the distinct ones).

The product of its digits is 28224, while the sum is 36.

The square root of 721972224 is about 26869.5408222768. The cubic root of 721972224 is about 897.0985674841.

The spelling of 721972224 in words is "seven hundred twenty-one million, nine hundred seventy-two thousand, two hundred twenty-four".