217861064 has 16 divisors (see below), whose sum is σ = 409706700. Its totient is φ = 108605952.

The previous prime is 217861057. The next prime is 217861067. The reversal of 217861064 is 460168712.

It can be written as a sum of positive squares in 2 ways, for example, as 217798564 + 62500 = 14758^2 + 250^2 .

It is not an unprimeable number, because it can be changed into a prime (217861067) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 37709 + ... + 43100.

Almost surely, 2^217861064 is an apocalyptic number.

It is an amenable number.

217861064 is a deficient number, since it is larger than the sum of its proper divisors (191845636).

217861064 is a wasteful number, since it uses less digits than its factorization.

217861064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81152 (or 81148 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 35.

The square root of 217861064 is about 14760.1173437070. The cubic root of 217861064 is about 601.7182818889.

The spelling of 217861064 in words is "two hundred seventeen million, eight hundred sixty-one thousand, sixty-four".