19621249 has 2 divisors, whose sum is σ = 19621250. Its totient is φ = 19621248.

The previous prime is 19621241. The next prime is 19621253. The reversal of 19621249 is 94212691.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12730624 + 6890625 = 3568^2 + 2625^2 .

It is a cyclic number.

It is not a de Polignac number, because 19621249 - 2³ = 19621241 is a prime.

It is not a weakly prime, because it can be changed into another prime (19621241) 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, 9810624 + 9810625.

It is an arithmetic number, because the mean of its divisors is an integer number (9810625).

Almost surely, 2^19621249 is an apocalyptic number.

It is an amenable number.

19621249 is a deficient number, since it is larger than the sum of its proper divisors (1).

19621249 is an equidigital number, since it uses as much as digits as its factorization.

19621249 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7776, while the sum is 34.

The square root of 19621249 is about 4429.5879040832. The cubic root of 19621249 is about 269.7173493853.

The spelling of 19621249 in words is "nineteen million, six hundred twenty-one thousand, two hundred forty-nine".