19782939851 has 2 divisors, whose sum is σ = 19782939852. Its totient is φ = 19782939850.

The previous prime is 19782939779. The next prime is 19782939857. The reversal of 19782939851 is 15893928791.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19782939851 is a prime.

It is not a weakly prime, because it can be changed into another prime (19782939857) 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, 9891469925 + 9891469926.

It is an arithmetic number, because the mean of its divisors is an integer number (9891469926).

Almost surely, 2^19782939851 is an apocalyptic number.

19782939851 is a deficient number, since it is larger than the sum of its proper divisors (1).

19782939851 is an equidigital number, since it uses as much as digits as its factorization.

19782939851 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9797760, while the sum is 62.

The spelling of 19782939851 in words is "nineteen billion, seven hundred eighty-two million, nine hundred thirty-nine thousand, eight hundred fifty-one".