217082978 has 16 divisors (see below), whose sum is σ = 372531264. Its totient is φ = 92938320.

The previous prime is 217082977. The next prime is 217082981. The reversal of 217082978 is 879280712.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (217082977) 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 7 ways as a sum of consecutive naturals, for example, 6701 + ... + 21887.

It is an arithmetic number, because the mean of its divisors is an integer number (23283204).

Almost surely, 2^217082978 is an apocalyptic number.

217082978 is a deficient number, since it is larger than the sum of its proper divisors (155448286).

217082978 is a wasteful number, since it uses less digits than its factorization.

217082978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16217.

The product of its (nonzero) digits is 112896, while the sum is 44.

The square root of 217082978 is about 14733.7360503031. The cubic root of 217082978 is about 601.0010861892.

The spelling of 217082978 in words is "two hundred seventeen million, eighty-two thousand, nine hundred seventy-eight".