66215503 has 2 divisors, whose sum is σ = 66215504. Its totient is φ = 66215502.

The previous prime is 66215483. The next prime is 66215519. The reversal of 66215503 is 30551266.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66215503 - 2²⁵ = 32661071 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66215543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33107751 + 33107752.

It is an arithmetic number, because the mean of its divisors is an integer number (33107752).

Almost surely, 2^66215503 is an apocalyptic number.

66215503 is a deficient number, since it is larger than the sum of its proper divisors (1).

66215503 is an equidigital number, since it uses as much as digits as its factorization.

66215503 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5400, while the sum is 28.

The square root of 66215503 is about 8137.2908882502. The cubic root of 66215503 is about 404.5633723541.

Adding to 66215503 its reverse (30551266), we get a palindrome (96766769).

The spelling of 66215503 in words is "sixty-six million, two hundred fifteen thousand, five hundred three".