721819899 has 12 divisors (see below), whose sum is σ = 1097504200. Its totient is φ = 455886144.

The previous prime is 721819871. The next prime is 721819933. The reversal of 721819899 is 998918127.

721819899 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 721819899 - 2¹¹ = 721817851 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (721819999) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2110414 + ... + 2110755.

Almost surely, 2^721819899 is an apocalyptic number.

721819899 is a deficient number, since it is larger than the sum of its proper divisors (375684301).

721819899 is a wasteful number, since it uses less digits than its factorization.

721819899 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4221194 (or 4221191 counting only the distinct ones).

The product of its digits is 653184, while the sum is 54.

The square root of 721819899 is about 26866.7061434780. The cubic root of 721819899 is about 897.0354717277.

The spelling of 721819899 in words is "seven hundred twenty-one million, eight hundred nineteen thousand, eight hundred ninety-nine".