721250928 has 120 divisors (see below), whose sum is σ = 2142541440. Its totient is φ = 226005120.

The previous prime is 721250917. The next prime is 721250983. The reversal of 721250928 is 829052127.

It is a super-2 number, since 2×721250928² = 1040405802281722368, which contains 22 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 721250892 and 721250901.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 193563 + ... + 197253.

It is an arithmetic number, because the mean of its divisors is an integer number (17854512).

Almost surely, 2^721250928 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 721250928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1071270720).

721250928 is an abundant number, since it is smaller than the sum of its proper divisors (1421290512).

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

721250928 is a wasteful number, since it uses less digits than its factorization.

721250928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3787 (or 3778 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 721250928 is about 26856.1152812539. The cubic root of 721250928 is about 896.7997151665.

The spelling of 721250928 in words is "seven hundred twenty-one million, two hundred fifty thousand, nine hundred twenty-eight".