245521321 has 2 divisors, whose sum is σ = 245521322. Its totient is φ = 245521320.

The previous prime is 245521313. The next prime is 245521349. The reversal of 245521321 is 123125542.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 173949721 + 71571600 = 13189^2 + 8460^2 .

It is a cyclic number.

It is not a de Polignac number, because 245521321 - 2³ = 245521313 is a prime.

It is not a weakly prime, because it can be changed into another prime (245521351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 122760660 + 122760661.

It is an arithmetic number, because the mean of its divisors is an integer number (122760661).

Almost surely, 2^245521321 is an apocalyptic number.

It is an amenable number.

245521321 is a deficient number, since it is larger than the sum of its proper divisors (1).

245521321 is an equidigital number, since it uses as much as digits as its factorization.

245521321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2400, while the sum is 25.

The square root of 245521321 is about 15669.1199816710. The cubic root of 245521321 is about 626.1759798465.

Adding to 245521321 its reverse (123125542), we get a palindrome (368646863).

The spelling of 245521321 in words is "two hundred forty-five million, five hundred twenty-one thousand, three hundred twenty-one".