505421681 has 2 divisors, whose sum is σ = 505421682. Its totient is φ = 505421680.

The previous prime is 505421677. The next prime is 505421687. The reversal of 505421681 is 186124505.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 460317025 + 45104656 = 21455^2 + 6716^2 .

It is a cyclic number.

It is not a de Polignac number, because 505421681 - 2² = 505421677 is a prime.

It is a super-3 number, since 3×505421681³ (a number of 27 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (505421687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 252710840 + 252710841.

It is an arithmetic number, because the mean of its divisors is an integer number (252710841).

Almost surely, 2^505421681 is an apocalyptic number.

It is an amenable number.

505421681 is a deficient number, since it is larger than the sum of its proper divisors (1).

505421681 is an equidigital number, since it uses as much as digits as its factorization.

505421681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9600, while the sum is 32.

The square root of 505421681 is about 22481.5853755913. The cubic root of 505421681 is about 796.5590129175.

The spelling of 505421681 in words is "five hundred five million, four hundred twenty-one thousand, six hundred eighty-one".