81087169 has 4 divisors (see below), whose sum is σ = 81118144. Its totient is φ = 81056196.

The previous prime is 81087157. The next prime is 81087187. The reversal of 81087169 is 96178018.

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 81087169 - 2⁵ = 81087137 is a prime.

It is a super-2 number, since 2×81087169² = 13150257952869122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81087469) 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, 11157 + ... + 16930.

It is an arithmetic number, because the mean of its divisors is an integer number (20279536).

Almost surely, 2^81087169 is an apocalyptic number.

It is an amenable number.

81087169 is a deficient number, since it is larger than the sum of its proper divisors (30975).

81087169 is a wasteful number, since it uses less digits than its factorization.

81087169 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30974.

The product of its (nonzero) digits is 24192, while the sum is 40.

The square root of 81087169 is about 9004.8414200362. The cubic root of 81087169 is about 432.8300246498.

The spelling of 81087169 in words is "eighty-one million, eighty-seven thousand, one hundred sixty-nine".