189896561 has 2 divisors, whose sum is σ = 189896562. Its totient is φ = 189896560.

The previous prime is 189896537. The next prime is 189896569. The reversal of 189896561 is 165698981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 145926400 + 43970161 = 12080^2 + 6631^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-189896561 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 (189896569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94948280 + 94948281.

It is an arithmetic number, because the mean of its divisors is an integer number (94948281).

Almost surely, 2^189896561 is an apocalyptic number.

It is an amenable number.

189896561 is a deficient number, since it is larger than the sum of its proper divisors (1).

189896561 is an equidigital number, since it uses as much as digits as its factorization.

189896561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 933120, while the sum is 53.

The square root of 189896561 is about 13780.2961143801. The cubic root of 189896561 is about 574.7853626117.

The spelling of 189896561 in words is "one hundred eighty-nine million, eight hundred ninety-six thousand, five hundred sixty-one".