53666516509 has 2 divisors, whose sum is σ = 53666516510. Its totient is φ = 53666516508.

The previous prime is 53666516411. The next prime is 53666516581. The reversal of 53666516509 is 90561566635.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 53602436484 + 64080025 = 231522^2 + 8005^2 .

It is a cyclic number.

It is not a de Polignac number, because 53666516509 - 2⁷ = 53666516381 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (53666516209) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 26833258254 + 26833258255.

It is an arithmetic number, because the mean of its divisors is an integer number (26833258255).

Almost surely, 2^53666516509 is an apocalyptic number.

It is an amenable number.

53666516509 is a deficient number, since it is larger than the sum of its proper divisors (1).

53666516509 is an equidigital number, since it uses as much as digits as its factorization.

53666516509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4374000, while the sum is 52.

The spelling of 53666516509 in words is "fifty-three billion, six hundred sixty-six million, five hundred sixteen thousand, five hundred nine".