72552221 has 16 divisors (see below), whose sum is σ = 84110208. Its totient is φ = 61300800.

The previous prime is 72552211. The next prime is 72552251. The reversal of 72552221 is 12225527.

It is a cyclic number.

It is not a de Polignac number, because 72552221 - 2¹⁰ = 72551197 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72552211) 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 15 ways as a sum of consecutive naturals, for example, 219026 + ... + 219356.

It is an arithmetic number, because the mean of its divisors is an integer number (5256888).

Almost surely, 2^72552221 is an apocalyptic number.

It is an amenable number.

72552221 is a deficient number, since it is larger than the sum of its proper divisors (11557987).

72552221 is a wasteful number, since it uses less digits than its factorization.

72552221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 692.

The product of its digits is 2800, while the sum is 26.

The square root of 72552221 is about 8517.7591536742. The cubic root of 72552221 is about 417.0776366134.

Adding to 72552221 its reverse (12225527), we get a palindrome (84777748).

The spelling of 72552221 in words is "seventy-two million, five hundred fifty-two thousand, two hundred twenty-one".