721317271 has 4 divisors (see below), whose sum is σ = 721964152. Its totient is φ = 720670392.

The previous prime is 721317239. The next prime is 721317323. The reversal of 721317271 is 172713127.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 172713127 = 1669 ⋅103483.

It is a cyclic number.

It is not a de Polignac number, because 721317271 - 2⁵ = 721317239 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 (721311271) 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, 321765 + ... + 323998.

It is an arithmetic number, because the mean of its divisors is an integer number (180491038).

Almost surely, 2^721317271 is an apocalyptic number.

721317271 is a deficient number, since it is larger than the sum of its proper divisors (646881).

721317271 is a wasteful number, since it uses less digits than its factorization.

721317271 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 646880.

The product of its digits is 4116, while the sum is 31.

The square root of 721317271 is about 26857.3504091524. The cubic root of 721317271 is about 896.8272111724.

The spelling of 721317271 in words is "seven hundred twenty-one million, three hundred seventeen thousand, two hundred seventy-one".