511005343661 has 2 divisors, whose sum is σ = 511005343662. Its totient is φ = 511005343660.

The previous prime is 511005343657. The next prime is 511005343669. The reversal of 511005343661 is 166343500115.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 331538730436 + 179466613225 = 575794^2 + 423635^2 .

It is a cyclic number.

It is not a de Polignac number, because 511005343661 - 2² = 511005343657 is a prime.

It is a super-2 number, since 2×511005343661² (a number of 24 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (511005343669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 255502671830 + 255502671831.

It is an arithmetic number, because the mean of its divisors is an integer number (255502671831).

Almost surely, 2^511005343661 is an apocalyptic number.

It is an amenable number.

511005343661 is a deficient number, since it is larger than the sum of its proper divisors (1).

511005343661 is an equidigital number, since it uses as much as digits as its factorization.

511005343661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32400, while the sum is 35.

Adding to 511005343661 its reverse (166343500115), we get a palindrome (677348843776).

The spelling of 511005343661 in words is "five hundred eleven billion, five million, three hundred forty-three thousand, six hundred sixty-one".