72106221 has 8 divisors (see below), whose sum is σ = 104881824. Its totient is φ = 43700720.

The previous prime is 72106171. The next prime is 72106241. The reversal of 72106221 is 12260127.

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 72106221 - 2¹⁰ = 72105197 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72106241) 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 7 ways as a sum of consecutive naturals, for example, 1092486 + ... + 1092551.

It is an arithmetic number, because the mean of its divisors is an integer number (13110228).

Almost surely, 2^72106221 is an apocalyptic number.

It is an amenable number.

72106221 is a deficient number, since it is larger than the sum of its proper divisors (32775603).

72106221 is a wasteful number, since it uses less digits than its factorization.

72106221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2185051.

The product of its (nonzero) digits is 336, while the sum is 21.

The square root of 72106221 is about 8491.5381998787. The cubic root of 72106221 is about 416.2212461087.

Adding to 72106221 its reverse (12260127), we get a palindrome (84366348).

It can be divided in two parts, 72106 and 221, that added together give a palindrome (72327).

The spelling of 72106221 in words is "seventy-two million, one hundred six thousand, two hundred twenty-one".