217240051 has 16 divisors (see below), whose sum is σ = 251463168. Its totient is φ = 183830400.

The previous prime is 217240039. The next prime is 217240087. The reversal of 217240051 is 150042712.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 217240051 - 2⁵ = 217240019 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (217240021) by changing a digit.

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, 220506 + ... + 221488.

It is an arithmetic number, because the mean of its divisors is an integer number (15716448).

Almost surely, 2^217240051 is an apocalyptic number.

217240051 is a deficient number, since it is larger than the sum of its proper divisors (34223117).

217240051 is a wasteful number, since it uses less digits than its factorization.

217240051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1362.

The product of its (nonzero) digits is 560, while the sum is 22.

The square root of 217240051 is about 14739.0654724104. The cubic root of 217240051 is about 601.1460050973.

Adding to 217240051 its reverse (150042712), we get a palindrome (367282763).

The spelling of 217240051 in words is "two hundred seventeen million, two hundred forty thousand, fifty-one".