81098189 has 4 divisors (see below), whose sum is σ = 81856224. Its totient is φ = 80340156.

The previous prime is 81098153. The next prime is 81098231. The reversal of 81098189 is 98189018.

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.

It is a cyclic number.

It is not a de Polignac number, because 81098189 - 2¹² = 81094093 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81092189) 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, 378857 + ... + 379070.

It is an arithmetic number, because the mean of its divisors is an integer number (20464056).

Almost surely, 2^81098189 is an apocalyptic number.

It is an amenable number.

81098189 is a deficient number, since it is larger than the sum of its proper divisors (758035).

81098189 is a wasteful number, since it uses less digits than its factorization.

81098189 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 758034.

The product of its (nonzero) digits is 41472, while the sum is 44.

The square root of 81098189 is about 9005.4532923113. The cubic root of 81098189 is about 432.8496314132.

The spelling of 81098189 in words is "eighty-one million, ninety-eight thousand, one hundred eighty-nine".