72221231 has 4 divisors (see below), whose sum is σ = 72922512. Its totient is φ = 71519952.

The previous prime is 72221197. The next prime is 72221239. The reversal of 72221231 is 13212227.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 72221231 - 2⁶ = 72221167 is a prime.

It is a super-2 number, since 2×72221231² = 10431812414310722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72221239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 350486 + ... + 350691.

It is an arithmetic number, because the mean of its divisors is an integer number (18230628).

Almost surely, 2^72221231 is an apocalyptic number.

72221231 is a deficient number, since it is larger than the sum of its proper divisors (701281).

72221231 is a wasteful number, since it uses less digits than its factorization.

72221231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 701280.

The product of its digits is 336, while the sum is 20.

The square root of 72221231 is about 8498.3075373865. The cubic root of 72221231 is about 416.4424206323.

Adding to 72221231 its reverse (13212227), we get a palindrome (85433458).

The spelling of 72221231 in words is "seventy-two million, two hundred twenty-one thousand, two hundred thirty-one".