81177198 has 8 divisors (see below), whose sum is σ = 162354408. Its totient is φ = 27059064.

The previous prime is 81177191. The next prime is 81177221. The reversal of 81177198 is 89177118.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

81177198 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81177191) 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, 6764761 + ... + 6764772.

It is an arithmetic number, because the mean of its divisors is an integer number (20294301).

Almost surely, 2^81177198 is an apocalyptic number.

81177198 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81177198 is a wasteful number, since it uses less digits than its factorization.

81177198 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13529538.

The product of its digits is 28224, while the sum is 42.

The square root of 81177198 is about 9009.8389552755. The cubic root of 81177198 is about 432.9901520872.

The spelling of 81177198 in words is "eighty-one million, one hundred seventy-seven thousand, one hundred ninety-eight".