189960861977 has 2 divisors, whose sum is σ = 189960861978. Its totient is φ = 189960861976.

The previous prime is 189960861931. The next prime is 189960861983. The reversal of 189960861977 is 779168069981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 183632818576 + 6328043401 = 428524^2 + 79549^2 .

It is a cyclic number.

It is not a de Polignac number, because 189960861977 - 2¹² = 189960857881 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 189960861977.

It is not a weakly prime, because it can be changed into another prime (189960861917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94980430988 + 94980430989.

It is an arithmetic number, because the mean of its divisors is an integer number (94980430989).

Almost surely, 2^189960861977 is an apocalyptic number.

It is an amenable number.

189960861977 is a deficient number, since it is larger than the sum of its proper divisors (1).

189960861977 is an equidigital number, since it uses as much as digits as its factorization.

189960861977 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 82301184, while the sum is 71.

The spelling of 189960861977 in words is "one hundred eighty-nine billion, nine hundred sixty million, eight hundred sixty-one thousand, nine hundred seventy-seven".