72106321 has 4 divisors (see below), whose sum is σ = 82407232. Its totient is φ = 61805412.

The previous prime is 72106301. The next prime is 72106327. The reversal of 72106321 is 12360127.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 72106321 - 2¹¹ = 72104273 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 72106292 and 72106301.

It is not an unprimeable number, because it can be changed into a prime (72106327) 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, 5150445 + ... + 5150458.

It is an arithmetic number, because the mean of its divisors is an integer number (20601808).

Almost surely, 2^72106321 is an apocalyptic number.

It is an amenable number.

72106321 is a deficient number, since it is larger than the sum of its proper divisors (10300911).

72106321 is a wasteful number, since it uses less digits than its factorization.

72106321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10300910.

The product of its (nonzero) digits is 504, while the sum is 22.

The square root of 72106321 is about 8491.5440880914. The cubic root of 72106321 is about 416.2214385198.

Adding to 72106321 its reverse (12360127), we get a palindrome (84466448).

It can be divided in two parts, 72106 and 321, that added together give a palindrome (72427).

The spelling of 72106321 in words is "seventy-two million, one hundred six thousand, three hundred twenty-one".