721419840 has 168 divisors, whose sum is σ = 2589507648. Its totient is φ = 183997440.

The previous prime is 721419833. The next prime is 721419857. The reversal of 721419840 is 48914127.

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 = 721419795 and 721419804.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 60795 + ... + 71685.

It is an arithmetic number, because the mean of its divisors is an integer number (15413736).

Almost surely, 2^721419840 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 721419840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1294753824).

721419840 is an abundant number, since it is smaller than the sum of its proper divisors (1868087808).

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

721419840 is a wasteful number, since it uses less digits than its factorization.

721419840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10937 (or 10924 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The square root of 721419840 is about 26859.2598557741. The cubic root of 721419840 is about 896.8697178077.

The spelling of 721419840 in words is "seven hundred twenty-one million, four hundred nineteen thousand, eight hundred forty".