245165621 has 2 divisors, whose sum is σ = 245165622. Its totient is φ = 245165620.

The previous prime is 245165617. The next prime is 245165689. The reversal of 245165621 is 126561542.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 176092900 + 69072721 = 13270^2 + 8311^2 .

It is a cyclic number.

It is not a de Polignac number, because 245165621 - 2² = 245165617 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is equal to p_13429256 and since 245165621 and 13429256 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (245165021) 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, 122582810 + 122582811.

It is an arithmetic number, because the mean of its divisors is an integer number (122582811).

Almost surely, 2^245165621 is an apocalyptic number.

It is an amenable number.

245165621 is a deficient number, since it is larger than the sum of its proper divisors (1).

245165621 is an equidigital number, since it uses as much as digits as its factorization.

245165621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14400, while the sum is 32.

The square root of 245165621 is about 15657.7655174677. The cubic root of 245165621 is about 625.8734420431.

The spelling of 245165621 in words is "two hundred forty-five million, one hundred sixty-five thousand, six hundred twenty-one".