189121831 has 4 divisors (see below), whose sum is σ = 189767592. Its totient is φ = 188476072.

The previous prime is 189121811. The next prime is 189121841. The reversal of 189121831 is 138121981.

It is a happy number.

189121831 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: 138121981 = 11369 ⋅12149.

It is a cyclic number.

It is not a de Polignac number, because 189121831 - 2¹⁵ = 189089063 is a prime.

It is a super-2 number, since 2×189121831² = 71534133921585122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (189121811) 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, 322441 + ... + 323026.

It is an arithmetic number, because the mean of its divisors is an integer number (47441898).

Almost surely, 2^189121831 is an apocalyptic number.

189121831 is a deficient number, since it is larger than the sum of its proper divisors (645761).

189121831 is an equidigital number, since it uses as much as digits as its factorization.

189121831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 645760.

The product of its digits is 3456, while the sum is 34.

The square root of 189121831 is about 13752.1573216714. The cubic root of 189121831 is about 574.0026375093.

The spelling of 189121831 in words is "one hundred eighty-nine million, one hundred twenty-one thousand, eight hundred thirty-one".