721608819 has 8 divisors (see below), whose sum is σ = 962269440. Its totient is φ = 481010376.

The previous prime is 721608787. The next prime is 721608821. The reversal of 721608819 is 918806127.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 721608819 - 2⁵ = 721608787 is a prime.

It is a super-2 number, since 2×721608819² = 1041438575317149522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (721608829) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 35274 + ... + 51840.

It is an arithmetic number, because the mean of its divisors is an integer number (120283680).

Almost surely, 2^721608819 is an apocalyptic number.

721608819 is a deficient number, since it is larger than the sum of its proper divisors (240660621).

721608819 is a wasteful number, since it uses less digits than its factorization.

721608819 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31089.

The product of its (nonzero) digits is 48384, while the sum is 42.

The square root of 721608819 is about 26862.7775741825. Note that the first 3 decimals coincide. The cubic root of 721608819 is about 896.9480239182.

The spelling of 721608819 in words is "seven hundred twenty-one million, six hundred eight thousand, eight hundred nineteen".