865852121 has 2 divisors, whose sum is σ = 865852122. Its totient is φ = 865852120.

The previous prime is 865852061. The next prime is 865852129. The reversal of 865852121 is 121258568.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 725548096 + 140304025 = 26936^2 + 11845^2 .

It is a cyclic number.

It is not a de Polignac number, because 865852121 - 2²² = 861657817 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (865852129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 432926060 + 432926061.

It is an arithmetic number, because the mean of its divisors is an integer number (432926061).

Almost surely, 2^865852121 is an apocalyptic number.

It is an amenable number.

865852121 is a deficient number, since it is larger than the sum of its proper divisors (1).

865852121 is an equidigital number, since it uses as much as digits as its factorization.

865852121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 38400, while the sum is 38.

The square root of 865852121 is about 29425.3652653625. The cubic root of 865852121 is about 953.1207146288.

The spelling of 865852121 in words is "eight hundred sixty-five million, eight hundred fifty-two thousand, one hundred twenty-one".