19425221 has 2 divisors, whose sum is σ = 19425222. Its totient is φ = 19425220.

The previous prime is 19425209. The next prime is 19425247. The reversal of 19425221 is 12252491.

It is an a-pointer prime, because the next prime (19425247) can be obtained adding 19425221 to its sum of digits (26).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12460900 + 6964321 = 3530^2 + 2639^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19425221 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19425421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9712610 + 9712611.

It is an arithmetic number, because the mean of its divisors is an integer number (9712611).

Almost surely, 2^19425221 is an apocalyptic number.

It is an amenable number.

19425221 is a deficient number, since it is larger than the sum of its proper divisors (1).

19425221 is an equidigital number, since it uses as much as digits as its factorization.

19425221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1440, while the sum is 26.

The square root of 19425221 is about 4407.4052457200. The cubic root of 19425221 is about 268.8161289585.

The spelling of 19425221 in words is "nineteen million, four hundred twenty-five thousand, two hundred twenty-one".