856405241 has 2 divisors, whose sum is σ = 856405242. Its totient is φ = 856405240.

The previous prime is 856405229. The next prime is 856405289. The reversal of 856405241 is 142504658.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 851472400 + 4932841 = 29180^2 + 2221^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-856405241 is a prime.

It is not a weakly prime, because it can be changed into another prime (856405201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 428202620 + 428202621.

It is an arithmetic number, because the mean of its divisors is an integer number (428202621).

Almost surely, 2^856405241 is an apocalyptic number.

It is an amenable number.

856405241 is a deficient number, since it is larger than the sum of its proper divisors (1).

856405241 is an equidigital number, since it uses as much as digits as its factorization.

856405241 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 38400, while the sum is 35.

The square root of 856405241 is about 29264.4022833203. The cubic root of 856405241 is about 949.6416898044.

Adding to 856405241 its reverse (142504658), we get a palindrome (998909899).

The spelling of 856405241 in words is "eight hundred fifty-six million, four hundred five thousand, two hundred forty-one".