189139687 has 4 divisors (see below), whose sum is σ = 206334216. Its totient is φ = 171945160.

The previous prime is 189139673. The next prime is 189139693. The reversal of 189139687 is 786931981.

It is a happy number.

189139687 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 786931981 = 11 ⋅71539271.

It is a cyclic number.

It is not a de Polignac number, because 189139687 - 2¹¹ = 189137639 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (189139607) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8597248 + ... + 8597269.

It is an arithmetic number, because the mean of its divisors is an integer number (51583554).

Almost surely, 2^189139687 is an apocalyptic number.

189139687 is a deficient number, since it is larger than the sum of its proper divisors (17194529).

189139687 is a wasteful number, since it uses less digits than its factorization.

189139687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17194528.

The product of its digits is 653184, while the sum is 52.

The square root of 189139687 is about 13752.8065135811. The cubic root of 189139687 is about 574.0207018235.

It can be divided in two parts, 189 and 139687, that added together give a square (139876 = 374²).

The spelling of 189139687 in words is "one hundred eighty-nine million, one hundred thirty-nine thousand, six hundred eighty-seven".