721319577823 has 4 divisors (see below), whose sum is σ = 776805699208. Its totient is φ = 665833456440.

The previous prime is 721319577821. The next prime is 721319577877. The reversal of 721319577823 is 328775913127.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 721319577823 - 2¹ = 721319577821 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721319577821) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27743060673 + ... + 27743060698.

It is an arithmetic number, because the mean of its divisors is an integer number (194201424802).

Almost surely, 2^721319577823 is an apocalyptic number.

721319577823 is a deficient number, since it is larger than the sum of its proper divisors (55486121385).

721319577823 is a wasteful number, since it uses less digits than its factorization.

721319577823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55486121384.

The product of its digits is 4445280, while the sum is 55.

The spelling of 721319577823 in words is "seven hundred twenty-one billion, three hundred nineteen million, five hundred seventy-seven thousand, eight hundred twenty-three".