189637661 has 2 divisors, whose sum is σ = 189637662. Its totient is φ = 189637660.

The previous prime is 189637579. The next prime is 189637667. The reversal of 189637661 is 166736981.

It is a happy number.

189637661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 184824025 + 4813636 = 13595^2 + 2194^2 .

It is an emirp because it is prime and its reverse (166736981) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 189637661 - 2¹⁰ = 189636637 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (189637667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94818830 + 94818831.

It is an arithmetic number, because the mean of its divisors is an integer number (94818831).

Almost surely, 2^189637661 is an apocalyptic number.

It is an amenable number.

189637661 is a deficient number, since it is larger than the sum of its proper divisors (1).

189637661 is an equidigital number, since it uses as much as digits as its factorization.

189637661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 326592, while the sum is 47.

The square root of 189637661 is about 13770.8990628789. The cubic root of 189637661 is about 574.5240280381.

The spelling of 189637661 in words is "one hundred eighty-nine million, six hundred thirty-seven thousand, six hundred sixty-one".