217082881 has 4 divisors (see below), whose sum is σ = 220322992. Its totient is φ = 213842772.

The previous prime is 217082869. The next prime is 217082891. The reversal of 217082881 is 188280712.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 217082881 - 2⁵ = 217082849 is a prime.

It is a super-2 number, since 2×217082881² = 94249954446520322, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 217082881.

It is not an unprimeable number, because it can be changed into a prime (217082891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1619955 + ... + 1620088.

It is an arithmetic number, because the mean of its divisors is an integer number (55080748).

Almost surely, 2^217082881 is an apocalyptic number.

It is an amenable number.

217082881 is a deficient number, since it is larger than the sum of its proper divisors (3240111).

217082881 is an equidigital number, since it uses as much as digits as its factorization.

217082881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3240110.

The product of its (nonzero) digits is 14336, while the sum is 37.

The square root of 217082881 is about 14733.7327585375. The cubic root of 217082881 is about 601.0009966733. Note that the first 3 decimals are identical.

The spelling of 217082881 in words is "two hundred seventeen million, eighty-two thousand, eight hundred eighty-one".