196561994129 has 2 divisors, whose sum is σ = 196561994130. Its totient is φ = 196561994128.

The previous prime is 196561994107. The next prime is 196561994149. The reversal of 196561994129 is 921499165691.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 163844419729 + 32717574400 = 404777^2 + 180880^2 .

It is a cyclic number.

It is not a de Polignac number, because 196561994129 - 2¹² = 196561990033 is a prime.

It is not a weakly prime, because it can be changed into another prime (196561994149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 98280997064 + 98280997065.

It is an arithmetic number, because the mean of its divisors is an integer number (98280997065).

Almost surely, 2^196561994129 is an apocalyptic number.

It is an amenable number.

196561994129 is a deficient number, since it is larger than the sum of its proper divisors (1).

196561994129 is an equidigital number, since it uses as much as digits as its factorization.

196561994129 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9447840, while the sum is 62.

The spelling of 196561994129 in words is "one hundred ninety-six billion, five hundred sixty-one million, nine hundred ninety-four thousand, one hundred twenty-nine".