81941217 has 8 divisors (see below), whose sum is σ = 109773600. Its totient is φ = 54368160.

The previous prime is 81941179. The next prime is 81941219. The reversal of 81941217 is 71214918.

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

It is not a de Polignac number, because 81941217 - 2⁷ = 81941089 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81941219) 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, 64092 + ... + 65357.

It is an arithmetic number, because the mean of its divisors is an integer number (13721700).

Almost surely, 2^81941217 is an apocalyptic number.

It is an amenable number.

81941217 is a deficient number, since it is larger than the sum of its proper divisors (27832383).

81941217 is a wasteful number, since it uses less digits than its factorization.

81941217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129663.

The product of its digits is 4032, while the sum is 33.

The square root of 81941217 is about 9052.1388080387. The cubic root of 81941217 is about 434.3443100792.

The spelling of 81941217 in words is "eighty-one million, nine hundred forty-one thousand, two hundred seventeen".