189918910997 has 2 divisors, whose sum is σ = 189918910998. Its totient is φ = 189918910996.

The previous prime is 189918910991. The next prime is 189918911029. The reversal of 189918910997 is 799019819981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 123897664081 + 66021246916 = 351991^2 + 256946^2 .

It is a cyclic number.

It is not a de Polignac number, because 189918910997 - 2⁶ = 189918910933 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 189918910997.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (189918910991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94959455498 + 94959455499.

It is an arithmetic number, because the mean of its divisors is an integer number (94959455499).

Almost surely, 2^189918910997 is an apocalyptic number.

It is an amenable number.

189918910997 is a deficient number, since it is larger than the sum of its proper divisors (1).

189918910997 is an equidigital number, since it uses as much as digits as its factorization.

189918910997 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 26453952, while the sum is 71.

The spelling of 189918910997 in words is "one hundred eighty-nine billion, nine hundred eighteen million, nine hundred ten thousand, nine hundred ninety-seven".