195121217 has 2 divisors, whose sum is σ = 195121218. Its totient is φ = 195121216.

The previous prime is 195121187. The next prime is 195121253. The reversal of 195121217 is 712121591.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 188485441 + 6635776 = 13729^2 + 2576^2 .

It is an emirp because it is prime and its reverse (712121591) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 195121217 - 2⁶ = 195121153 is a prime.

It is a super-2 number, since 2×195121217² = 76144578647122178, which contains 22 as substring.

It is a Chen prime.

It is equal to p_10823924 and since 195121217 and 10823924 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 195121217.

It is not a weakly prime, because it can be changed into another prime (195121117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97560608 + 97560609.

It is an arithmetic number, because the mean of its divisors is an integer number (97560609).

Almost surely, 2^195121217 is an apocalyptic number.

It is an amenable number.

195121217 is a deficient number, since it is larger than the sum of its proper divisors (1).

195121217 is an equidigital number, since it uses as much as digits as its factorization.

195121217 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1260, while the sum is 29.

The square root of 195121217 is about 13968.5796343078. The cubic root of 195121217 is about 580.0091328328.

The spelling of 195121217 in words is "one hundred ninety-five million, one hundred twenty-one thousand, two hundred seventeen".