721913472 has 400 divisors, whose sum is σ = 2592745650. Its totient is φ = 199148544.

The previous prime is 721913429. The next prime is 721913509. The reversal of 721913472 is 274319127.

It can be written as a sum of positive squares in only one way, i.e., 609892416 + 112021056 = 24696^2 + 10584^2 .

It is a super-2 number, since 2×721913472² = 1042318122110189568, which contains 22 as substring.

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

It is a nude number because it is divisible by every one of its digits and also a Zuckerman number because it is divisible by the product of its digits.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 49 ways as a sum of consecutive naturals, for example, 24893554 + ... + 24893582.

Almost surely, 2^721913472 is an apocalyptic number.

721913472 is a gapful number since it is divisible by the number (72) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 721913472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1296372825).

721913472 is an abundant number, since it is smaller than the sum of its proper divisors (1870832178).

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

721913472 is an frugal number, since it uses more digits than its factorization.

721913472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83 (or 41 counting only the distinct ones).

The product of its digits is 21168, while the sum is 36.

The square root of 721913472 is about 26868.4475174879. The cubic root of 721913472 is about 897.0742323998.

The spelling of 721913472 in words is "seven hundred twenty-one million, nine hundred thirteen thousand, four hundred seventy-two".