502501561 has 2 divisors, whose sum is σ = 502501562. Its totient is φ = 502501560.

The previous prime is 502501543. The next prime is 502501583. The reversal of 502501561 is 165105205.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 451307536 + 51194025 = 21244^2 + 7155^2 .

It is a cyclic number.

It is not a de Polignac number, because 502501561 - 2²¹ = 500404409 is a prime.

It is not a weakly prime, because it can be changed into another prime (502511561) 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, 251250780 + 251250781.

It is an arithmetic number, because the mean of its divisors is an integer number (251250781).

Almost surely, 2^502501561 is an apocalyptic number.

It is an amenable number.

502501561 is a deficient number, since it is larger than the sum of its proper divisors (1).

502501561 is an equidigital number, since it uses as much as digits as its factorization.

502501561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1500, while the sum is 25.

The square root of 502501561 is about 22416.5465895173. The cubic root of 502501561 is about 795.0219848093.

Adding to 502501561 its reverse (165105205), we get a palindrome (667606766).

The spelling of 502501561 in words is "five hundred two million, five hundred one thousand, five hundred sixty-one".