189216881 has 12 divisors (see below), whose sum is σ = 220373172. Its totient is φ = 161991648.

The previous prime is 189216869. The next prime is 189216889. The reversal of 189216881 is 188612981.

189216881 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 174662656 + 14554225 = 13216^2 + 3815^2 .

It is not a de Polignac number, because 189216881 - 2¹⁸ = 188954737 is a prime.

It is a super-2 number, since 2×189216881² = 71606056110736322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (189216889) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 51791 + ... + 55323.

It is an arithmetic number, because the mean of its divisors is an integer number (18364431).

Almost surely, 2^189216881 is an apocalyptic number.

It is an amenable number.

189216881 is a deficient number, since it is larger than the sum of its proper divisors (31156291).

189216881 is a wasteful number, since it uses less digits than its factorization.

189216881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4640 (or 4633 counting only the distinct ones).

The product of its digits is 55296, while the sum is 44.

The square root of 189216881 is about 13755.6127089999. The cubic root of 189216881 is about 574.0987833160.

The spelling of 189216881 in words is "one hundred eighty-nine million, two hundred sixteen thousand, eight hundred eighty-one".