19872217 has 2 divisors, whose sum is σ = 19872218. Its totient is φ = 19872216.

The previous prime is 19872197. The next prime is 19872227. The reversal of 19872217 is 71227891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12138256 + 7733961 = 3484^2 + 2781^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19872217 is a prime.

It is not a weakly prime, because it can be changed into another prime (19872227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9936108 + 9936109.

It is an arithmetic number, because the mean of its divisors is an integer number (9936109).

Almost surely, 2^19872217 is an apocalyptic number.

It is an amenable number.

19872217 is a deficient number, since it is larger than the sum of its proper divisors (1).

19872217 is an equidigital number, since it uses as much as digits as its factorization.

19872217 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14112, while the sum is 37.

The square root of 19872217 is about 4457.8264883237. The cubic root of 19872217 is about 270.8624320503.

The spelling of 19872217 in words is "nineteen million, eight hundred seventy-two thousand, two hundred seventeen".