19428121 has 2 divisors, whose sum is σ = 19428122. Its totient is φ = 19428120.

The previous prime is 19428109. The next prime is 19428163. The reversal of 19428121 is 12182491.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19360000 + 68121 = 4400^2 + 261^2 .

It is a cyclic number.

It is not a de Polignac number, because 19428121 - 2⁹ = 19427609 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19428121.

It is not a weakly prime, because it can be changed into another prime (19423121) 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 as a sum of consecutive naturals, namely, 9714060 + 9714061.

It is an arithmetic number, because the mean of its divisors is an integer number (9714061).

Almost surely, 2^19428121 is an apocalyptic number.

It is an amenable number.

19428121 is a deficient number, since it is larger than the sum of its proper divisors (1).

19428121 is an equidigital number, since it uses as much as digits as its factorization.

19428121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1152, while the sum is 28.

The square root of 19428121 is about 4407.7342252001. The cubic root of 19428121 is about 268.8295055199.

The spelling of 19428121 in words is "nineteen million, four hundred twenty-eight thousand, one hundred twenty-one".