81098111 has 4 divisors (see below), whose sum is σ = 81934272. Its totient is φ = 80261952.

The previous prime is 81098107. The next prime is 81098113. The reversal of 81098111 is 11189018.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11189018 = 2 ⋅5594509.

It is a cyclic number.

It is not a de Polignac number, because 81098111 - 2² = 81098107 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81098113) 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, 417935 + ... + 418128.

It is an arithmetic number, because the mean of its divisors is an integer number (20483568).

Almost surely, 2^81098111 is an apocalyptic number.

81098111 is a deficient number, since it is larger than the sum of its proper divisors (836161).

81098111 is an equidigital number, since it uses as much as digits as its factorization.

81098111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 836160.

The product of its (nonzero) digits is 576, while the sum is 29.

The square root of 81098111 is about 9005.4489616010. The cubic root of 81098111 is about 432.8494926420.

The spelling of 81098111 in words is "eighty-one million, ninety-eight thousand, one hundred eleven".