19625989 has 2 divisors, whose sum is σ = 19625990. Its totient is φ = 19625988.

The previous prime is 19625981. The next prime is 19626001. The reversal of 19625989 is 98952691.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19624900 + 1089 = 4430^2 + 33^2 .

It is a cyclic number.

It is not a de Polignac number, because 19625989 - 2³ = 19625981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19625981) 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, 9812994 + 9812995.

It is an arithmetic number, because the mean of its divisors is an integer number (9812995).

Almost surely, 2^19625989 is an apocalyptic number.

It is an amenable number.

19625989 is a deficient number, since it is larger than the sum of its proper divisors (1).

19625989 is an equidigital number, since it uses as much as digits as its factorization.

19625989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 349920, while the sum is 49.

The square root of 19625989 is about 4430.1229102588. The cubic root of 19625989 is about 269.7390666114.

The spelling of 19625989 in words is "nineteen million, six hundred twenty-five thousand, nine hundred eighty-nine".