205102004621 has 2 divisors, whose sum is σ = 205102004622. Its totient is φ = 205102004620.

The previous prime is 205102004609. The next prime is 205102004647. The reversal of 205102004621 is 126400201502.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 167947514596 + 37154490025 = 409814^2 + 192755^2 .

It is a cyclic number.

It is not a de Polignac number, because 205102004621 - 2³⁰ = 204028262797 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205102004221) 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, 102551002310 + 102551002311.

It is an arithmetic number, because the mean of its divisors is an integer number (102551002311).

Almost surely, 2^205102004621 is an apocalyptic number.

It is an amenable number.

205102004621 is a deficient number, since it is larger than the sum of its proper divisors (1).

205102004621 is an equidigital number, since it uses as much as digits as its factorization.

205102004621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 960, while the sum is 23.

The spelling of 205102004621 in words is "two hundred five billion, one hundred two million, four thousand, six hundred twenty-one".