72556217 has 4 divisors (see below), whose sum is σ = 72788340. Its totient is φ = 72324096.

The previous prime is 72556201. The next prime is 72556219. The reversal of 72556217 is 71265527.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 24960016 + 47596201 = 4996^2 + 6899^2 .

It is a cyclic number.

It is not a de Polignac number, because 72556217 - 2⁴ = 72556201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72556219) 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, 115592 + ... + 116217.

It is an arithmetic number, because the mean of its divisors is an integer number (18197085).

Almost surely, 2^72556217 is an apocalyptic number.

It is an amenable number.

72556217 is a deficient number, since it is larger than the sum of its proper divisors (232123).

72556217 is a wasteful number, since it uses less digits than its factorization.

72556217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 232122.

The product of its digits is 29400, while the sum is 35.

The square root of 72556217 is about 8517.9937191806. The cubic root of 72556217 is about 417.0852936803.

The spelling of 72556217 in words is "seventy-two million, five hundred fifty-six thousand, two hundred seventeen".