2178936157 has 2 divisors, whose sum is σ = 2178936158. Its totient is φ = 2178936156.

The previous prime is 2178936077. The next prime is 2178936187. The reversal of 2178936157 is 7516398712.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1971892836 + 207043321 = 44406^2 + 14389^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2178936157 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2178936157.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2178936187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1089468078 + 1089468079.

It is an arithmetic number, because the mean of its divisors is an integer number (1089468079).

Almost surely, 2^2178936157 is an apocalyptic number.

It is an amenable number.

2178936157 is a deficient number, since it is larger than the sum of its proper divisors (1).

2178936157 is an equidigital number, since it uses as much as digits as its factorization.

2178936157 is an evil number, because the sum of its binary digits is even.

The product of its digits is 635040, while the sum is 49.

The square root of 2178936157 is about 46679.0762226503. The cubic root of 2178936157 is about 1296.4273022371.

The spelling of 2178936157 in words is "two billion, one hundred seventy-eight million, nine hundred thirty-six thousand, one hundred fifty-seven".