81201766 has 8 divisors (see below), whose sum is σ = 121854024. Its totient is φ = 40583760.

The previous prime is 81201761. The next prime is 81201767. The reversal of 81201766 is 66710218.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81201761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1455 + ... + 12826.

It is an arithmetic number, because the mean of its divisors is an integer number (15231753).

Almost surely, 2^81201766 is an apocalyptic number.

81201766 is a deficient number, since it is larger than the sum of its proper divisors (40652258).

81201766 is a wasteful number, since it uses less digits than its factorization.

81201766 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17126.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 81201766 is about 9011.2022505324. The cubic root of 81201766 is about 433.0338286751.

The spelling of 81201766 in words is "eighty-one million, two hundred one thousand, seven hundred sixty-six".