245145221 has 2 divisors, whose sum is σ = 245145222. Its totient is φ = 245145220.

The previous prime is 245145217. The next prime is 245145223. The reversal of 245145221 is 122541542.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 237930625 + 7214596 = 15425^2 + 2686^2 .

It is a cyclic number.

It is not a de Polignac number, because 245145221 - 2² = 245145217 is a prime.

Together with 245145223, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (245145223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 122572610 + 122572611.

It is an arithmetic number, because the mean of its divisors is an integer number (122572611).

Almost surely, 2^245145221 is an apocalyptic number.

It is an amenable number.

245145221 is a deficient number, since it is larger than the sum of its proper divisors (1).

245145221 is an equidigital number, since it uses as much as digits as its factorization.

245145221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3200, while the sum is 26.

The square root of 245145221 is about 15657.1140699683. The cubic root of 245145221 is about 625.8560821154.

Adding to 245145221 its reverse (122541542), we get a palindrome (367686763).

The spelling of 245145221 in words is "two hundred forty-five million, one hundred forty-five thousand, two hundred twenty-one".