19928171 has 2 divisors, whose sum is σ = 19928172. Its totient is φ = 19928170.

The previous prime is 19928149. The next prime is 19928177. The reversal of 19928171 is 17182991.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 19928171 - 2¹⁸ = 19666027 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (19928177) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9964085 + 9964086.

It is an arithmetic number, because the mean of its divisors is an integer number (9964086).

Almost surely, 2^19928171 is an apocalyptic number.

19928171 is a deficient number, since it is larger than the sum of its proper divisors (1).

19928171 is an equidigital number, since it uses as much as digits as its factorization.

19928171 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9072, while the sum is 38.

The square root of 19928171 is about 4464.0980051966. The cubic root of 19928171 is about 271.1164153548.

The spelling of 19928171 in words is "nineteen million, nine hundred twenty-eight thousand, one hundred seventy-one".