19900000387 has 2 divisors, whose sum is σ = 19900000388. Its totient is φ = 19900000386.

The previous prime is 19900000363. The next prime is 19900000397. The reversal of 19900000387 is 78300000991.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19900000387 is a prime.

It is not a weakly prime, because it can be changed into another prime (19900000397) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9950000193 + 9950000194.

It is an arithmetic number, because the mean of its divisors is an integer number (9950000194).

Almost surely, 2^19900000387 is an apocalyptic number.

19900000387 is a deficient number, since it is larger than the sum of its proper divisors (1).

19900000387 is an equidigital number, since it uses as much as digits as its factorization.

19900000387 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13608, while the sum is 37.

The spelling of 19900000387 in words is "nineteen billion, nine hundred million, three hundred eighty-seven", and thus it is an aban number.