189107521 has 4 divisors (see below), whose sum is σ = 195628500. Its totient is φ = 182586544.

The previous prime is 189107519. The next prime is 189107537. The reversal of 189107521 is 125701981.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 125701981 = 293 ⋅429017.

It can be written as a sum of positive squares in 2 ways, for example, as 137827600 + 51279921 = 11740^2 + 7161^2 .

It is a cyclic number.

It is not a de Polignac number, because 189107521 - 2¹ = 189107519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (189102521) 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, 3260446 + ... + 3260503.

It is an arithmetic number, because the mean of its divisors is an integer number (48907125).

Almost surely, 2^189107521 is an apocalyptic number.

It is an amenable number.

189107521 is a deficient number, since it is larger than the sum of its proper divisors (6520979).

189107521 is an equidigital number, since it uses as much as digits as its factorization.

189107521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6520978.

The product of its (nonzero) digits is 5040, while the sum is 34.

The square root of 189107521 is about 13751.6370298230. The cubic root of 189107521 is about 573.9881597431.

The spelling of 189107521 in words is "one hundred eighty-nine million, one hundred seven thousand, five hundred twenty-one".