72221321 has 8 divisors (see below), whose sum is σ = 76930560. Its totient is φ = 67563328.

The previous prime is 72221297. The next prime is 72221323. The reversal of 72221321 is 12312227.

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 72221321 - 2⁶ = 72221257 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 72221293 and 72221302.

It is not an unprimeable number, because it can be changed into a prime (72221323) 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, 9881 + ... + 15558.

It is an arithmetic number, because the mean of its divisors is an integer number (9616320).

Almost surely, 2^72221321 is an apocalyptic number.

It is an amenable number.

72221321 is a deficient number, since it is larger than the sum of its proper divisors (4709239).

72221321 is a wasteful number, since it uses less digits than its factorization.

72221321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25623.

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

The square root of 72221321 is about 8498.3128325568. The cubic root of 72221321 is about 416.4425936184.

Adding to 72221321 its reverse (12312227), we get a palindrome (84533548).

The spelling of 72221321 in words is "seventy-two million, two hundred twenty-one thousand, three hundred twenty-one".