721311231 has 8 divisors (see below), whose sum is σ = 1012366720. Its totient is φ = 455564952.

The previous prime is 721311191. The next prime is 721311233. The reversal of 721311231 is 132113127.

It is a happy number.

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

It is not a de Polignac number, because 721311231 - 2¹⁰ = 721310207 is a prime.

It is a super-2 number, since 2×721311231² = 1040579783933470722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 721311198 and 721311207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721311233) 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, 6327235 + ... + 6327348.

It is an arithmetic number, because the mean of its divisors is an integer number (126545840).

Almost surely, 2^721311231 is an apocalyptic number.

721311231 is a deficient number, since it is larger than the sum of its proper divisors (291055489).

721311231 is a wasteful number, since it uses less digits than its factorization.

721311231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12654605.

The product of its digits is 252, while the sum is 21.

The square root of 721311231 is about 26857.2379629775. The cubic root of 721311231 is about 896.8247079506.

Adding to 721311231 its reverse (132113127), we get a palindrome (853424358).

The spelling of 721311231 in words is "seven hundred twenty-one million, three hundred eleven thousand, two hundred thirty-one".