857220187 has 2 divisors, whose sum is σ = 857220188. Its totient is φ = 857220186.

The previous prime is 857220151. The next prime is 857220191. The reversal of 857220187 is 781022758.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-857220187 is a prime.

It is not a weakly prime, because it can be changed into another prime (857223187) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 428610093 + 428610094.

It is an arithmetic number, because the mean of its divisors is an integer number (428610094).

Almost surely, 2^857220187 is an apocalyptic number.

857220187 is a deficient number, since it is larger than the sum of its proper divisors (1).

857220187 is an equidigital number, since it uses as much as digits as its factorization.

857220187 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 62720, while the sum is 40.

The square root of 857220187 is about 29278.3228174020. The cubic root of 857220187 is about 949.9428172414.

The spelling of 857220187 in words is "eight hundred fifty-seven million, two hundred twenty thousand, one hundred eighty-seven".