189404681 has 2 divisors, whose sum is σ = 189404682. Its totient is φ = 189404680.

The previous prime is 189404671. The next prime is 189404687. The reversal of 189404681 is 186404981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 189337600 + 67081 = 13760^2 + 259^2 .

It is a cyclic number.

It is not a de Polignac number, because 189404681 - 2⁶ = 189404617 is a prime.

It is a super-2 number, since 2×189404681² = 71748266369423522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (189404687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94702340 + 94702341.

It is an arithmetic number, because the mean of its divisors is an integer number (94702341).

Almost surely, 2^189404681 is an apocalyptic number.

It is an amenable number.

189404681 is a deficient number, since it is larger than the sum of its proper divisors (1).

189404681 is an equidigital number, since it uses as much as digits as its factorization.

189404681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 55296, while the sum is 41.

The square root of 189404681 is about 13762.4373204749. The cubic root of 189404681 is about 574.2886537989.

The spelling of 189404681 in words is "one hundred eighty-nine million, four hundred four thousand, six hundred eighty-one".