721330001 has 4 divisors (see below), whose sum is σ = 824377152. Its totient is φ = 618282852.

The previous prime is 721329991. The next prime is 721330007. The reversal of 721330001 is 100033127.

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 721330001 - 2¹⁴ = 721313617 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (721330007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51523565 + ... + 51523578.

It is an arithmetic number, because the mean of its divisors is an integer number (206094288).

Almost surely, 2^721330001 is an apocalyptic number.

It is an amenable number.

721330001 is a deficient number, since it is larger than the sum of its proper divisors (103047151).

721330001 is a wasteful number, since it uses less digits than its factorization.

721330001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103047150.

The product of its (nonzero) digits is 126, while the sum is 17.

The square root of 721330001 is about 26857.5874009562. The cubic root of 721330001 is about 896.8324869568.

Adding to 721330001 its reverse (100033127), we get a palindrome (821363128).

The spelling of 721330001 in words is "seven hundred twenty-one million, three hundred thirty thousand, one".