721675621 has 8 divisors (see below), whose sum is σ = 733108320. Its totient is φ = 710308272.

The previous prime is 721675609. The next prime is 721675627. The reversal of 721675621 is 126576127.

721675621 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 721675621 - 2²³ = 713287013 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721675627) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6166 + ... + 38488.

It is an arithmetic number, because the mean of its divisors is an integer number (91638540).

Almost surely, 2^721675621 is an apocalyptic number.

It is an amenable number.

721675621 is a deficient number, since it is larger than the sum of its proper divisors (11432699).

721675621 is a wasteful number, since it uses less digits than its factorization.

721675621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32675.

The product of its digits is 35280, while the sum is 37.

The square root of 721675621 is about 26864.0209387947. The cubic root of 721675621 is about 896.9757009973.

The spelling of 721675621 in words is "seven hundred twenty-one million, six hundred seventy-five thousand, six hundred twenty-one".