19697841851 has 2 divisors, whose sum is σ = 19697841852. Its totient is φ = 19697841850.

The previous prime is 19697841763. The next prime is 19697841857. The reversal of 19697841851 is 15814879691.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19697841851 is a prime.

It is not a weakly prime, because it can be changed into another prime (19697841857) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9848920925 + 9848920926.

It is an arithmetic number, because the mean of its divisors is an integer number (9848920926).

Almost surely, 2^19697841851 is an apocalyptic number.

19697841851 is a deficient number, since it is larger than the sum of its proper divisors (1).

19697841851 is an equidigital number, since it uses as much as digits as its factorization.

19697841851 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4354560, while the sum is 59.

The spelling of 19697841851 in words is "nineteen billion, six hundred ninety-seven million, eight hundred forty-one thousand, eight hundred fifty-one".