27979506157 has 4 divisors (see below), whose sum is σ = 27983975580. Its totient is φ = 27975036736.

The previous prime is 27979506143. The next prime is 27979506161. The reversal of 27979506157 is 75160597972.

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 17943674116 + 10035832041 = 133954^2 + 100179^2 .

It is a cyclic number.

It is not a de Polignac number, because 27979506157 - 2⁷ = 27979506029 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 (27979506197) 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, 2225308 + ... + 2237845.

It is an arithmetic number, because the mean of its divisors is an integer number (6995993895).

Almost surely, 2^27979506157 is an apocalyptic number.

It is an amenable number.

27979506157 is a deficient number, since it is larger than the sum of its proper divisors (4469423).

27979506157 is an equidigital number, since it uses as much as digits as its factorization.

27979506157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4469422.

The product of its (nonzero) digits is 8334900, while the sum is 58.

The spelling of 27979506157 in words is "twenty-seven billion, nine hundred seventy-nine million, five hundred six thousand, one hundred fifty-seven".