721205073 has 64 divisors (see below), whose sum is σ = 1140705280. Its totient is φ = 449717184.

The previous prime is 721205071. The next prime is 721205081. The reversal of 721205073 is 370502127.

It is not a de Polignac number, because 721205073 - 2¹ = 721205071 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (721205071) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 4424490 + ... + 4424652.

It is an arithmetic number, because the mean of its divisors is an integer number (17823520).

Almost surely, 2^721205073 is an apocalyptic number.

It is an amenable number.

721205073 is a deficient number, since it is larger than the sum of its proper divisors (419500207).

721205073 is a wasteful number, since it uses less digits than its factorization.

721205073 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 355 (or 349 counting only the distinct ones).

The product of its (nonzero) digits is 2940, while the sum is 27.

The square root of 721205073 is about 26855.2615515098. The cubic root of 721205073 is about 896.7807094729.

The spelling of 721205073 in words is "seven hundred twenty-one million, two hundred five thousand, seventy-three".