505506265721 has 2 divisors, whose sum is σ = 505506265722. Its totient is φ = 505506265720.

The previous prime is 505506265711. The next prime is 505506265741. The reversal of 505506265721 is 127562605505.

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., 500726064400 + 4780201321 = 707620^2 + 69139^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-505506265721 is a prime.

It is not a weakly prime, because it can be changed into another prime (505506265711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 252753132860 + 252753132861.

It is an arithmetic number, because the mean of its divisors is an integer number (252753132861).

Almost surely, 2^505506265721 is an apocalyptic number.

It is an amenable number.

505506265721 is a deficient number, since it is larger than the sum of its proper divisors (1).

505506265721 is an equidigital number, since it uses as much as digits as its factorization.

505506265721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 630000, while the sum is 44.

The spelling of 505506265721 in words is "five hundred five billion, five hundred six million, two hundred sixty-five thousand, seven hundred twenty-one".