245843821 has 2 divisors, whose sum is σ = 245843822. Its totient is φ = 245843820.

The previous prime is 245843789. The next prime is 245843833. The reversal of 245843821 is 128348542.

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., 203775625 + 42068196 = 14275^2 + 6486^2 .

It is a cyclic number.

It is not a de Polignac number, because 245843821 - 2⁵ = 245843789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (245843861) 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, 122921910 + 122921911.

It is an arithmetic number, because the mean of its divisors is an integer number (122921911).

Almost surely, 2^245843821 is an apocalyptic number.

It is an amenable number.

245843821 is a deficient number, since it is larger than the sum of its proper divisors (1).

245843821 is an equidigital number, since it uses as much as digits as its factorization.

245843821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 61440, while the sum is 37.

The square root of 245843821 is about 15679.4075462053. The cubic root of 245843821 is about 626.4500271922.

The spelling of 245843821 in words is "two hundred forty-five million, eight hundred forty-three thousand, eight hundred twenty-one".