721397016 has 96 divisors (see below), whose sum is σ = 2132894400. Its totient is φ = 227797920.

The previous prime is 721396993. The next prime is 721397021. The reversal of 721397016 is 610793127.

It is a happy number.

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

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, 27171 + ... + 46701.

It is an arithmetic number, because the mean of its divisors is an integer number (22217650).

Almost surely, 2^721397016 is an apocalyptic number.

721397016 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 721397016, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1066447200).

721397016 is an abundant number, since it is smaller than the sum of its proper divisors (1411497384).

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

721397016 is a wasteful number, since it uses less digits than its factorization.

721397016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19571 (or 19555 counting only the distinct ones).

The product of its (nonzero) digits is 15876, while the sum is 36.

The square root of 721397016 is about 26858.8349710109. The cubic root of 721397016 is about 896.8602594363.

The spelling of 721397016 in words is "seven hundred twenty-one million, three hundred ninety-seven thousand, sixteen".