27978157 has 2 divisors, whose sum is σ = 27978158. Its totient is φ = 27978156.

The previous prime is 27978149. The next prime is 27978163. The reversal of 27978157 is 75187972.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 24314761 + 3663396 = 4931^2 + 1914^2 .

It is a cyclic number.

It is not a de Polignac number, because 27978157 - 2³ = 27978149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27978187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13989078 + 13989079.

It is an arithmetic number, because the mean of its divisors is an integer number (13989079).

Almost surely, 2^27978157 is an apocalyptic number.

It is an amenable number.

27978157 is a deficient number, since it is larger than the sum of its proper divisors (1).

27978157 is an equidigital number, since it uses as much as digits as its factorization.

27978157 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 246960, while the sum is 46.

The square root of 27978157 is about 5289.4382499468. The cubic root of 27978157 is about 303.5799144875.

The spelling of 27978157 in words is "twenty-seven million, nine hundred seventy-eight thousand, one hundred fifty-seven".