189478561 has 2 divisors, whose sum is σ = 189478562. Its totient is φ = 189478560.

The previous prime is 189478537. The next prime is 189478571. The reversal of 189478561 is 165874981.

189478561 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., 188925025 + 553536 = 13745^2 + 744^2 .

It is an emirp because it is prime and its reverse (165874981) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 189478561 - 2⁵ = 189478529 is a prime.

It is a Chen prime.

It is an alternating number because its digits alternate between odd and even.

It is not a weakly prime, because it can be changed into another prime (189478571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94739280 + 94739281.

It is an arithmetic number, because the mean of its divisors is an integer number (94739281).

Almost surely, 2^189478561 is an apocalyptic number.

It is an amenable number.

189478561 is a deficient number, since it is larger than the sum of its proper divisors (1).

189478561 is an equidigital number, since it uses as much as digits as its factorization.

189478561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 483840, while the sum is 49.

The square root of 189478561 is about 13765.1211763646. The cubic root of 189478561 is about 574.3633139219.

The spelling of 189478561 in words is "one hundred eighty-nine million, four hundred seventy-eight thousand, five hundred sixty-one".