721130256 has 480 divisors, whose sum is σ = 2781964800. Its totient is φ = 176359680.

The previous prime is 721130251. The next prime is 721130297. The reversal of 721130256 is 652031127.

It is a happy number.

721130256 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×721130256² = 1040057692237251072, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721130251) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 4424031 + ... + 4424193.

It is an arithmetic number, because the mean of its divisors is an integer number (5795760).

Almost surely, 2^721130256 is an apocalyptic number.

721130256 is a gapful number since it is divisible by the number (76) 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 721130256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1390982400).

721130256 is an abundant number, since it is smaller than the sum of its proper divisors (2060834544).

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

721130256 is a wasteful number, since it uses less digits than its factorization.

721130256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 224 (or 205 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 27.

The square root of 721130256 is about 26853.8685481254. The cubic root of 721130256 is about 896.7496980611.

The spelling of 721130256 in words is "seven hundred twenty-one million, one hundred thirty thousand, two hundred fifty-six".