217564045 has 16 divisors (see below), whose sum is σ = 285355008. Its totient is φ = 158526720.

The previous prime is 217564037. The next prime is 217564069. The reversal of 217564045 is 540465712.

It is not a de Polignac number, because 217564045 - 2³ = 217564037 is a prime.

It is a super-2 number, since 2×217564045² = 94668227353524050, 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 217564045.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38649 + ... + 43918.

It is an arithmetic number, because the mean of its divisors is an integer number (17834688).

Almost surely, 2^217564045 is an apocalyptic number.

It is an amenable number.

217564045 is a deficient number, since it is larger than the sum of its proper divisors (67790963).

217564045 is a wasteful number, since it uses less digits than its factorization.

217564045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82620.

The product of its (nonzero) digits is 33600, while the sum is 34.

The square root of 217564045 is about 14750.0523727884. The cubic root of 217564045 is about 601.4447083856. Note that the first 3 decimals are identical.

The spelling of 217564045 in words is "two hundred seventeen million, five hundred sixty-four thousand, forty-five".