855146221 has 2 divisors, whose sum is σ = 855146222. Its totient is φ = 855146220.

The previous prime is 855146147. The next prime is 855146239. The reversal of 855146221 is 122641558.

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., 805992100 + 49154121 = 28390^2 + 7011^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-855146221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (855146021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 427573110 + 427573111.

It is an arithmetic number, because the mean of its divisors is an integer number (427573111).

Almost surely, 2^855146221 is an apocalyptic number.

It is an amenable number.

855146221 is a deficient number, since it is larger than the sum of its proper divisors (1).

855146221 is an equidigital number, since it uses as much as digits as its factorization.

855146221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 19200, while the sum is 34.

The square root of 855146221 is about 29242.8832538791. The cubic root of 855146221 is about 949.1760985931.

Adding to 855146221 its reverse (122641558), we get a palindrome (977787779).

The spelling of 855146221 in words is "eight hundred fifty-five million, one hundred forty-six thousand, two hundred twenty-one".