72221161 has 8 divisors (see below), whose sum is σ = 73165824. Its totient is φ = 71281200.

The previous prime is 72221153. The next prime is 72221167. The reversal of 72221161 is 16112227.

It is a happy number.

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 72221161 - 2³ = 72221153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72221167) 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, 37750 + ... + 39616.

It is an arithmetic number, because the mean of its divisors is an integer number (9145728).

Almost surely, 2^72221161 is an apocalyptic number.

It is an amenable number.

72221161 is a deficient number, since it is larger than the sum of its proper divisors (944663).

72221161 is a wasteful number, since it uses less digits than its factorization.

72221161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2351.

The product of its digits is 336, while the sum is 22.

The square root of 72221161 is about 8498.3034189184. The cubic root of 72221161 is about 416.4422860875.

Adding to 72221161 its reverse (16112227), we get a palindrome (88333388).

The spelling of 72221161 in words is "seventy-two million, two hundred twenty-one thousand, one hundred sixty-one".