81764081 has 8 divisors (see below), whose sum is σ = 96459264. Its totient is φ = 67822560.

The previous prime is 81764071. The next prime is 81764083. The reversal of 81764081 is 18046718.

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

It is a cyclic number.

It is not a de Polignac number, because 81764081 - 2⁶ = 81764017 is a prime.

It is a super-2 number, since 2×81764081² = 13370729883549122, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (81764083) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 188180 + ... + 188613.

It is an arithmetic number, because the mean of its divisors is an integer number (12057408).

Almost surely, 2^81764081 is an apocalyptic number.

It is an amenable number.

81764081 is a deficient number, since it is larger than the sum of its proper divisors (14695183).

81764081 is a wasteful number, since it uses less digits than its factorization.

81764081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 376831.

The product of its (nonzero) digits is 10752, while the sum is 35.

The square root of 81764081 is about 9042.3493075638. The cubic root of 81764081 is about 434.0311037616.

The spelling of 81764081 in words is "eighty-one million, seven hundred sixty-four thousand, eighty-one".