81199766 has 8 divisors (see below), whose sum is σ = 122877864. Its totient is φ = 40240480.

The previous prime is 81199751. The next prime is 81199771. The reversal of 81199766 is 66799118.

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

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 81199766.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 179420 + ... + 179871.

It is an arithmetic number, because the mean of its divisors is an integer number (15359733).

Almost surely, 2^81199766 is an apocalyptic number.

81199766 is a deficient number, since it is larger than the sum of its proper divisors (41678098).

81199766 is a wasteful number, since it uses less digits than its factorization.

81199766 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 359406.

The product of its digits is 163296, while the sum is 47.

The square root of 81199766 is about 9011.0912768654. The cubic root of 81199766 is about 433.0302734373.

The spelling of 81199766 in words is "eighty-one million, one hundred ninety-nine thousand, seven hundred sixty-six".