19657740871 has 2 divisors, whose sum is σ = 19657740872. Its totient is φ = 19657740870.

The previous prime is 19657740821. The next prime is 19657740881. The reversal of 19657740871 is 17804775691.

It is a strong prime.

It is an emirp because it is prime and its reverse (17804775691) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19657740871 - 2⁷ = 19657740743 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19657740811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9828870435 + 9828870436.

It is an arithmetic number, because the mean of its divisors is an integer number (9828870436).

Almost surely, 2^19657740871 is an apocalyptic number.

19657740871 is a deficient number, since it is larger than the sum of its proper divisors (1).

19657740871 is an equidigital number, since it uses as much as digits as its factorization.

19657740871 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2963520, while the sum is 55.

The spelling of 19657740871 in words is "nineteen billion, six hundred fifty-seven million, seven hundred forty thousand, eight hundred seventy-one".