72706221 has 48 divisors (see below), whose sum is σ = 126967680. Its totient is φ = 40279680.

The previous prime is 72706211. The next prime is 72706237. The reversal of 72706221 is 12260727.

It is not a de Polignac number, because 72706221 - 2⁶ = 72706157 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72706211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 258601 + ... + 258881.

It is an arithmetic number, because the mean of its divisors is an integer number (2645160).

Almost surely, 2^72706221 is an apocalyptic number.

It is an amenable number.

72706221 is a deficient number, since it is larger than the sum of its proper divisors (54261459).

72706221 is a wasteful number, since it uses less digits than its factorization.

72706221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 371 (or 328 counting only the distinct ones).

The product of its (nonzero) digits is 2352, while the sum is 27.

The square root of 72706221 is about 8526.7942979762. The cubic root of 72706221 is about 417.3725256540.

Adding to 72706221 its reverse (12260727), we get a palindrome (84966948).

It can be divided in two parts, 72706 and 221, that added together give a palindrome (72927).

The spelling of 72706221 in words is "seventy-two million, seven hundred six thousand, two hundred twenty-one".