2178157 has 2 divisors, whose sum is σ = 2178158. Its totient is φ = 2178156.

The previous prime is 2178151. The next prime is 2178173. The reversal of 2178157 is 7518712.

It is a happy number.

2178157 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2056356 + 121801 = 1434^2 + 349^2 .

It is a cyclic number.

It is not a de Polignac number, because 2178157 - 2³ = 2178149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2178151) 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 as a sum of consecutive naturals, namely, 1089078 + 1089079.

It is an arithmetic number, because the mean of its divisors is an integer number (1089079).

2^2178157 is an apocalyptic number.

It is an amenable number.

2178157 is a deficient number, since it is larger than the sum of its proper divisors (1).

2178157 is an equidigital number, since it uses as much as digits as its factorization.

2178157 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3920, while the sum is 31.

The square root of 2178157 is about 1475.8580555053. The cubic root of 2178157 is about 129.6272755743.

The spelling of 2178157 in words is "two million, one hundred seventy-eight thousand, one hundred fifty-seven".