721438859 has 4 divisors (see below), whose sum is σ = 728581920. Its totient is φ = 714295800.

The previous prime is 721438853. The next prime is 721438871. The reversal of 721438859 is 958834127.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-721438859 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (721438853) 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, 3571379 + ... + 3571580.

It is an arithmetic number, because the mean of its divisors is an integer number (182145480).

Almost surely, 2^721438859 is an apocalyptic number.

721438859 is a deficient number, since it is larger than the sum of its proper divisors (7143061).

721438859 is a wasteful number, since it uses less digits than its factorization.

721438859 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7143060.

The product of its digits is 483840, while the sum is 47.

The square root of 721438859 is about 26859.6139026606. The cubic root of 721438859 is about 896.8775992171.

The spelling of 721438859 in words is "seven hundred twenty-one million, four hundred thirty-eight thousand, eight hundred fifty-nine".