66504553 has 4 divisors (see below), whose sum is σ = 66521088. Its totient is φ = 66488020.

The previous prime is 66504539. The next prime is 66504587. The reversal of 66504553 is 35540566.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 66504553 - 2⁵ = 66504521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66504253) 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 in 3 ways as a sum of consecutive naturals, for example, 2100 + ... + 11722.

It is an arithmetic number, because the mean of its divisors is an integer number (16630272).

Almost surely, 2^66504553 is an apocalyptic number.

It is an amenable number.

66504553 is a deficient number, since it is larger than the sum of its proper divisors (16535).

66504553 is an equidigital number, since it uses as much as digits as its factorization.

66504553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16534.

The product of its (nonzero) digits is 54000, while the sum is 34.

The square root of 66504553 is about 8155.0323727132. The cubic root of 66504553 is about 405.1511969131.

The spelling of 66504553 in words is "sixty-six million, five hundred four thousand, five hundred fifty-three".