189111021 has 12 divisors (see below), whose sum is σ = 277154976. Its totient is φ = 114612520.

The previous prime is 189111019. The next prime is 189111023. The reversal of 189111021 is 120111981.

It is an interprime number because it is at equal distance from previous prime (189111019) and next prime (189111023).

It is not a de Polignac number, because 189111021 - 2¹ = 189111019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 189110982 and 189111000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (189111023) 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, 260121 + ... + 260846.

It is an arithmetic number, because the mean of its divisors is an integer number (23096248).

Almost surely, 2^189111021 is an apocalyptic number.

189111021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

189111021 is a deficient number, since it is larger than the sum of its proper divisors (88043955).

189111021 is a wasteful number, since it uses less digits than its factorization.

189111021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 520992 (or 520981 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 24.

The square root of 189111021 is about 13751.7642868106. The cubic root of 189111021 is about 573.9917008436.

The spelling of 189111021 in words is "one hundred eighty-nine million, one hundred eleven thousand, twenty-one".