189715561 has 4 divisors (see below), whose sum is σ = 216817792. Its totient is φ = 162613332.

The previous prime is 189715553. The next prime is 189715579. The reversal of 189715561 is 165517981.

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.

It is not a de Polignac number, because 189715561 - 2³ = 189715553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (189715061) 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, 13551105 + ... + 13551118.

It is an arithmetic number, because the mean of its divisors is an integer number (54204448).

Almost surely, 2^189715561 is an apocalyptic number.

It is an amenable number.

189715561 is a deficient number, since it is larger than the sum of its proper divisors (27102231).

189715561 is an equidigital number, since it uses as much as digits as its factorization.

189715561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27102230.

The product of its digits is 75600, while the sum is 43.

The square root of 189715561 is about 13773.7272007253. The cubic root of 189715561 is about 574.6026855767.

The spelling of 189715561 in words is "one hundred eighty-nine million, seven hundred fifteen thousand, five hundred sixty-one".