19249921 has 2 divisors, whose sum is σ = 19249922. Its totient is φ = 19249920.

The previous prime is 19249913. The next prime is 19249949. The reversal of 19249921 is 12994291.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15681600 + 3568321 = 3960^2 + 1889^2 .

It is a cyclic number.

It is not a de Polignac number, because 19249921 - 2³ = 19249913 is a prime.

It is not a weakly prime, because it can be changed into another prime (19249961) 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, 9624960 + 9624961.

It is an arithmetic number, because the mean of its divisors is an integer number (9624961).

Almost surely, 2^19249921 is an apocalyptic number.

It is an amenable number.

19249921 is a deficient number, since it is larger than the sum of its proper divisors (1).

19249921 is an equidigital number, since it uses as much as digits as its factorization.

19249921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11664, while the sum is 37.

The square root of 19249921 is about 4387.4731908013. The cubic root of 19249921 is about 268.0050539256.

The spelling of 19249921 in words is "nineteen million, two hundred forty-nine thousand, nine hundred twenty-one".