19893221 has 2 divisors, whose sum is σ = 19893222. Its totient is φ = 19893220.

The previous prime is 19893197. The next prime is 19893253. The reversal of 19893221 is 12239891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16900321 + 2992900 = 4111^2 + 1730^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19893221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19893271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9946610 + 9946611.

It is an arithmetic number, because the mean of its divisors is an integer number (9946611).

Almost surely, 2^19893221 is an apocalyptic number.

It is an amenable number.

19893221 is a deficient number, since it is larger than the sum of its proper divisors (1).

19893221 is an equidigital number, since it uses as much as digits as its factorization.

19893221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7776, while the sum is 35.

The square root of 19893221 is about 4460.1817227553. The cubic root of 19893221 is about 270.9578280714.

The spelling of 19893221 in words is "nineteen million, eight hundred ninety-three thousand, two hundred twenty-one".