189735581 has 4 divisors (see below), whose sum is σ = 216840672. Its totient is φ = 162630492.

The previous prime is 189735529. The next prime is 189735583. The reversal of 189735581 is 185537981.

It is a happy number.

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: 185537981 = 71 ⋅2613211.

It is a cyclic number.

It is not a de Polignac number, because 189735581 - 2¹⁴ = 189719197 is a prime.

It is a super-2 number, since 2×189735581² = 71999181394815122, 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 (189735583) 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, 13552535 + ... + 13552548.

It is an arithmetic number, because the mean of its divisors is an integer number (54210168).

Almost surely, 2^189735581 is an apocalyptic number.

It is an amenable number.

189735581 is a deficient number, since it is larger than the sum of its proper divisors (27105091).

189735581 is an equidigital number, since it uses as much as digits as its factorization.

189735581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27105090.

The product of its digits is 302400, while the sum is 47.

The square root of 189735581 is about 13774.4539274702. The cubic root of 189735581 is about 574.6228967832.

The spelling of 189735581 in words is "one hundred eighty-nine million, seven hundred thirty-five thousand, five hundred eighty-one".