721673673793 has 4 divisors (see below), whose sum is σ = 721675373488. Its totient is φ = 721671974100.

The previous prime is 721673673779. The next prime is 721673673839. The reversal of 721673673793 is 397376376127.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 721673673793 - 2¹⁷ = 721673542721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (721673673293) 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, 389230 + ... + 1262872.

It is an arithmetic number, because the mean of its divisors is an integer number (180418843372).

Almost surely, 2^721673673793 is an apocalyptic number.

It is an amenable number.

721673673793 is a deficient number, since it is larger than the sum of its proper divisors (1699695).

721673673793 is an equidigital number, since it uses as much as digits as its factorization.

721673673793 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1699694.

The product of its digits is 42007896, while the sum is 61.

The spelling of 721673673793 in words is "seven hundred twenty-one billion, six hundred seventy-three million, six hundred seventy-three thousand, seven hundred ninety-three".