17982157 has 4 divisors (see below), whose sum is σ = 18001980. Its totient is φ = 17962336.

The previous prime is 17982143. The next prime is 17982179. The reversal of 17982157 is 75128971.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 75128971 = 23 ⋅3266477.

It can be written as a sum of positive squares in 2 ways, for example, as 13734436 + 4247721 = 3706^2 + 2061^2 .

It is a cyclic number.

It is not a de Polignac number, because 17982157 - 2¹⁵ = 17949389 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 (17982857) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8482 + ... + 10387.

It is an arithmetic number, because the mean of its divisors is an integer number (4500495).

Almost surely, 2^17982157 is an apocalyptic number.

It is an amenable number.

17982157 is a deficient number, since it is larger than the sum of its proper divisors (19823).

17982157 is an equidigital number, since it uses as much as digits as its factorization.

17982157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19822.

The product of its digits is 35280, while the sum is 40.

The square root of 17982157 is about 4240.5373480256. The cubic root of 17982157 is about 261.9875147013.

The spelling of 17982157 in words is "seventeen million, nine hundred eighty-two thousand, one hundred fifty-seven".