194978857 has 2 divisors, whose sum is σ = 194978858. Its totient is φ = 194978856.

The previous prime is 194978801. The next prime is 194978879. The reversal of 194978857 is 758879491.

194978857 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 153363456 + 41615401 = 12384^2 + 6451^2 .

It is an emirp because it is prime and its reverse (758879491) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-194978857 is a prime.

It is not a weakly prime, because it can be changed into another prime (194978957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97489428 + 97489429.

It is an arithmetic number, because the mean of its divisors is an integer number (97489429).

Almost surely, 2^194978857 is an apocalyptic number.

It is an amenable number.

194978857 is a deficient number, since it is larger than the sum of its proper divisors (1).

194978857 is an equidigital number, since it uses as much as digits as its factorization.

194978857 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5080320, while the sum is 58.

The square root of 194978857 is about 13963.4829824081. The cubic root of 194978857 is about 579.8680407285.

The spelling of 194978857 in words is "one hundred ninety-four million, nine hundred seventy-eight thousand, eight hundred fifty-seven".