245855221 has 2 divisors, whose sum is σ = 245855222. Its totient is φ = 245855220.

The previous prime is 245855219. The next prime is 245855263. The reversal of 245855221 is 122558542.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 244578321 + 1276900 = 15639^2 + 1130^2 .

It is a cyclic number.

It is not a de Polignac number, because 245855221 - 2¹ = 245855219 is a prime.

Together with 245855219, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (245855201) 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, 122927610 + 122927611.

It is an arithmetic number, because the mean of its divisors is an integer number (122927611).

Almost surely, 2^245855221 is an apocalyptic number.

It is an amenable number.

245855221 is a deficient number, since it is larger than the sum of its proper divisors (1).

245855221 is an equidigital number, since it uses as much as digits as its factorization.

245855221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 32000, while the sum is 34.

The square root of 245855221 is about 15679.7710761350. The cubic root of 245855221 is about 626.4597100604.

The spelling of 245855221 in words is "two hundred forty-five million, eight hundred fifty-five thousand, two hundred twenty-one".