66551503 has 2 divisors, whose sum is σ = 66551504. Its totient is φ = 66551502.

The previous prime is 66551501. The next prime is 66551519. The reversal of 66551503 is 30515566.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66551503 - 2¹ = 66551501 is a prime.

Together with 66551501, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66551501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33275751 + 33275752.

It is an arithmetic number, because the mean of its divisors is an integer number (33275752).

Almost surely, 2^66551503 is an apocalyptic number.

66551503 is a deficient number, since it is larger than the sum of its proper divisors (1).

66551503 is an equidigital number, since it uses as much as digits as its factorization.

66551503 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13500, while the sum is 31.

The square root of 66551503 is about 8157.9104555027. The cubic root of 66551503 is about 405.2465155709.

The spelling of 66551503 in words is "sixty-six million, five hundred fifty-one thousand, five hundred three".