505660081 has 2 divisors, whose sum is σ = 505660082. Its totient is φ = 505660080.

The previous prime is 505660079. The next prime is 505660097. The reversal of 505660081 is 180066505.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 351900081 + 153760000 = 18759^2 + 12400^2 .

It is a cyclic number.

It is not a de Polignac number, because 505660081 - 2¹ = 505660079 is a prime.

It is a super-2 number, since 2×505660081² = 511384235033853122, which contains 22 as substring.

Together with 505660079, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (505660381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 252830040 + 252830041.

It is an arithmetic number, because the mean of its divisors is an integer number (252830041).

Almost surely, 2^505660081 is an apocalyptic number.

It is an amenable number.

505660081 is a deficient number, since it is larger than the sum of its proper divisors (1).

505660081 is an equidigital number, since it uses as much as digits as its factorization.

505660081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7200, while the sum is 31.

The square root of 505660081 is about 22486.8868676836. The cubic root of 505660081 is about 796.6842349687.

The spelling of 505660081 in words is "five hundred five million, six hundred sixty thousand, eighty-one".