72221647 has 2 divisors, whose sum is σ = 72221648. Its totient is φ = 72221646.

The previous prime is 72221561. The next prime is 72221671. The reversal of 72221647 is 74612227.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72221647 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72221047) 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 as a sum of consecutive naturals, namely, 36110823 + 36110824.

It is an arithmetic number, because the mean of its divisors is an integer number (36110824).

Almost surely, 2^72221647 is an apocalyptic number.

72221647 is a deficient number, since it is larger than the sum of its proper divisors (1).

72221647 is an equidigital number, since it uses as much as digits as its factorization.

72221647 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9408, while the sum is 31.

The square root of 72221647 is about 8498.3320128129. The cubic root of 72221647 is about 416.4432202112.

The spelling of 72221647 in words is "seventy-two million, two hundred twenty-one thousand, six hundred forty-seven".