189561913 has 2 divisors, whose sum is σ = 189561914. Its totient is φ = 189561912.

The previous prime is 189561899. The next prime is 189561919. The reversal of 189561913 is 319165981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 179238544 + 10323369 = 13388^2 + 3213^2 .

It is an emirp because it is prime and its reverse (319165981) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 189561913 - 2⁵ = 189561881 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 189561913.

It is not a weakly prime, because it can be changed into another prime (189561919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94780956 + 94780957.

It is an arithmetic number, because the mean of its divisors is an integer number (94780957).

Almost surely, 2^189561913 is an apocalyptic number.

It is an amenable number.

189561913 is a deficient number, since it is larger than the sum of its proper divisors (1).

189561913 is an equidigital number, since it uses as much as digits as its factorization.

189561913 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 58320, while the sum is 43.

The square root of 189561913 is about 13768.1484957128. The cubic root of 189561913 is about 574.4475227675.

The spelling of 189561913 in words is "one hundred eighty-nine million, five hundred sixty-one thousand, nine hundred thirteen".