721696266816 has 448 divisors, whose sum is σ = 2328029822976. Its totient is φ = 192965068800.

The previous prime is 721696266799. The next prime is 721696266827. The reversal of 721696266816 is 618662696127.

It is a tau number, because it is divible by the number of its divisors (448).

It is a self number, because there is not a number n which added to its sum of digits gives 721696266816.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 184527901 + ... + 184531811.

Almost surely, 2^721696266816 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 721696266816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1164014911488).

721696266816 is an abundant number, since it is smaller than the sum of its proper divisors (1606333556160).

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

721696266816 is a wasteful number, since it uses less digits than its factorization.

721696266816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4110 (or 4100 counting only the distinct ones).

The product of its digits is 15676416, while the sum is 60.

The spelling of 721696266816 in words is "seven hundred twenty-one billion, six hundred ninety-six million, two hundred sixty-six thousand, eight hundred sixteen".