217182157 has 4 divisors (see below), whose sum is σ = 229957596. Its totient is φ = 204406720.

The previous prime is 217182151. The next prime is 217182167. The reversal of 217182157 is 751281712.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 127103076 + 90079081 = 11274^2 + 9491^2 .

It is a cyclic number.

It is not a de Polignac number, because 217182157 - 2²³ = 208793549 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217182151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6387694 + ... + 6387727.

It is an arithmetic number, because the mean of its divisors is an integer number (57489399).

Almost surely, 2^217182157 is an apocalyptic number.

It is an amenable number.

217182157 is a deficient number, since it is larger than the sum of its proper divisors (12775439).

217182157 is a wasteful number, since it uses less digits than its factorization.

217182157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12775438.

The product of its digits is 7840, while the sum is 34.

The square root of 217182157 is about 14737.1013771366. The cubic root of 217182157 is about 601.0925989862.

The spelling of 217182157 in words is "two hundred seventeen million, one hundred eighty-two thousand, one hundred fifty-seven".