721623110509 has 16 divisors (see below), whose sum is σ = 868916838400. Its totient is φ = 585440471664.

The previous prime is 721623110503. The next prime is 721623110519. The reversal of 721623110509 is 905011326127.

It is a cyclic number.

It is not a de Polignac number, because 721623110509 - 2²¹ = 721621013357 is a prime.

It is a super-3 number, since 3×721623110509³ (a number of 37 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721623110503) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 2351169 + ... + 2640310.

It is an arithmetic number, because the mean of its divisors is an integer number (54307302400).

Almost surely, 2^721623110509 is an apocalyptic number.

It is an amenable number.

721623110509 is a deficient number, since it is larger than the sum of its proper divisors (147293727891).

721623110509 is a wasteful number, since it uses less digits than its factorization.

721623110509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4992592.

The product of its (nonzero) digits is 22680, while the sum is 37.

The spelling of 721623110509 in words is "seven hundred twenty-one billion, six hundred twenty-three million, one hundred ten thousand, five hundred nine".