19749051787 has 2 divisors, whose sum is σ = 19749051788. Its totient is φ = 19749051786.

The previous prime is 19749051781. The next prime is 19749051841. The reversal of 19749051787 is 78715094791.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19749051787 is a prime.

It is not a weakly prime, because it can be changed into another prime (19749051781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9874525893 + 9874525894.

It is an arithmetic number, because the mean of its divisors is an integer number (9874525894).

Almost surely, 2^19749051787 is an apocalyptic number.

19749051787 is a deficient number, since it is larger than the sum of its proper divisors (1).

19749051787 is an equidigital number, since it uses as much as digits as its factorization.

19749051787 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4445280, while the sum is 58.

The spelling of 19749051787 in words is "nineteen billion, seven hundred forty-nine million, fifty-one thousand, seven hundred eighty-seven".