721239001 has 16 divisors (see below), whose sum is σ = 835902720. Its totient is φ = 609523200.

The previous prime is 721238989. The next prime is 721239011. The reversal of 721239001 is 100932127.

It is a cyclic number.

It is not a de Polignac number, because 721239001 - 2⁷ = 721238873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (721239011) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 248380 + ... + 251266.

It is an arithmetic number, because the mean of its divisors is an integer number (52243920).

Almost surely, 2^721239001 is an apocalyptic number.

It is an amenable number.

721239001 is a deficient number, since it is larger than the sum of its proper divisors (114663719).

721239001 is a wasteful number, since it uses less digits than its factorization.

721239001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3384.

The product of its (nonzero) digits is 756, while the sum is 25.

The square root of 721239001 is about 26855.8932266272. The cubic root of 721239001 is about 896.7947718157.

The spelling of 721239001 in words is "seven hundred twenty-one million, two hundred thirty-nine thousand, one".