721383673 has 4 divisors (see below), whose sum is σ = 723287440. Its totient is φ = 719479908.

The previous prime is 721383667. The next prime is 721383739. The reversal of 721383673 is 376383127.

It is a happy number.

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.

It is a cyclic number.

It is not a de Polignac number, because 721383673 - 2⁹ = 721383161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (721383623) 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, 951315 + ... + 952072.

It is an arithmetic number, because the mean of its divisors is an integer number (180821860).

Almost surely, 2^721383673 is an apocalyptic number.

It is an amenable number.

721383673 is a deficient number, since it is larger than the sum of its proper divisors (1903767).

721383673 is a wasteful number, since it uses less digits than its factorization.

721383673 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1903766.

The product of its digits is 127008, while the sum is 40.

The square root of 721383673 is about 26858.5865785972. The cubic root of 721383673 is about 896.8547299429.

The spelling of 721383673 in words is "seven hundred twenty-one million, three hundred eighty-three thousand, six hundred seventy-three".