189938221 has 4 divisors (see below), whose sum is σ = 207205344. Its totient is φ = 172671100.

The previous prime is 189938213. The next prime is 189938227. The reversal of 189938221 is 122839981.

189938221 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 a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 122839981 = 11 ⋅11167271.

It is a cyclic number.

It is not a de Polignac number, because 189938221 - 2³ = 189938213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (189938227) 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, 8633545 + ... + 8633566.

It is an arithmetic number, because the mean of its divisors is an integer number (51801336).

Almost surely, 2^189938221 is an apocalyptic number.

189938221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

189938221 is a deficient number, since it is larger than the sum of its proper divisors (17267123).

189938221 is a wasteful number, since it uses less digits than its factorization.

189938221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17267122.

The product of its digits is 62208, while the sum is 43.

The square root of 189938221 is about 13781.8076100343. The cubic root of 189938221 is about 574.8273921728.

The spelling of 189938221 in words is "one hundred eighty-nine million, nine hundred thirty-eight thousand, two hundred twenty-one".