27998181157 has 8 divisors (see below), whose sum is σ = 28534539384. Its totient is φ = 27462122688.

The previous prime is 27998181151. The next prime is 27998181187. The reversal of 27998181157 is 75118189972.

It can be written as a sum of positive squares in 4 ways, for example, as 5842156356 + 22156024801 = 76434^2 + 148849^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-27998181157 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 (27998181151) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 118383 + ... + 264595.

It is an arithmetic number, because the mean of its divisors is an integer number (3566817423).

Almost surely, 2^27998181157 is an apocalyptic number.

It is an amenable number.

27998181157 is a deficient number, since it is larger than the sum of its proper divisors (536358227).

27998181157 is a wasteful number, since it uses less digits than its factorization.

27998181157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149879.

The product of its digits is 2540160, while the sum is 58.

The spelling of 27998181157 in words is "twenty-seven billion, nine hundred ninety-eight million, one hundred eighty-one thousand, one hundred fifty-seven".