19625061809 has 2 divisors, whose sum is σ = 19625061810. Its totient is φ = 19625061808.

The previous prime is 19625061793. The next prime is 19625061821. The reversal of 19625061809 is 90816052691.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13260213409 + 6364848400 = 115153^2 + 79780^2 .

It is a cyclic number.

It is not a de Polignac number, because 19625061809 - 2⁴ = 19625061793 is a prime.

It is not a weakly prime, because it can be changed into another prime (19625061889) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9812530904 + 9812530905.

It is an arithmetic number, because the mean of its divisors is an integer number (9812530905).

Almost surely, 2^19625061809 is an apocalyptic number.

It is an amenable number.

19625061809 is a deficient number, since it is larger than the sum of its proper divisors (1).

19625061809 is an equidigital number, since it uses as much as digits as its factorization.

19625061809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 233280, while the sum is 47.

The spelling of 19625061809 in words is "nineteen billion, six hundred twenty-five million, sixty-one thousand, eight hundred nine".