502499001661 has 2 divisors, whose sum is σ = 502499001662. Its totient is φ = 502499001660.

The previous prime is 502499001647. The next prime is 502499001671. The reversal of 502499001661 is 166100994205.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 492900880761 + 9598120900 = 702069^2 + 97970^2 .

It is a cyclic number.

It is not a de Polignac number, because 502499001661 - 2²¹ = 502496904509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (502499001671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 251249500830 + 251249500831.

It is an arithmetic number, because the mean of its divisors is an integer number (251249500831).

Almost surely, 2^502499001661 is an apocalyptic number.

It is an amenable number.

502499001661 is a deficient number, since it is larger than the sum of its proper divisors (1).

502499001661 is an equidigital number, since it uses as much as digits as its factorization.

502499001661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 116640, while the sum is 43.

Adding to 502499001661 its reverse (166100994205), we get a palindrome (668599995866).

The spelling of 502499001661 in words is "five hundred two billion, four hundred ninety-nine million, one thousand, six hundred sixty-one".