19778300197 has 2 divisors, whose sum is σ = 19778300198. Its totient is φ = 19778300196.

The previous prime is 19778300149. The next prime is 19778300207. The reversal of 19778300197 is 79100387791.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19528944516 + 249355681 = 139746^2 + 15791^2 .

It is a cyclic number.

It is not a de Polignac number, because 19778300197 - 2¹⁵ = 19778267429 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19778300117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9889150098 + 9889150099.

It is an arithmetic number, because the mean of its divisors is an integer number (9889150099).

Almost surely, 2^19778300197 is an apocalyptic number.

It is an amenable number.

19778300197 is a deficient number, since it is larger than the sum of its proper divisors (1).

19778300197 is an equidigital number, since it uses as much as digits as its factorization.

19778300197 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 666792, while the sum is 52.

The spelling of 19778300197 in words is "nineteen billion, seven hundred seventy-eight million, three hundred thousand, one hundred ninety-seven".