66513555 has 20 divisors (see below), whose sum is σ = 119232432. Its totient is φ = 35473680.

The previous prime is 66513533. The next prime is 66513619. The reversal of 66513555 is 55531566.

It is not a de Polignac number, because 66513555 - 2¹³ = 66505363 is a prime.

It is an unprimeable number.

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 19 ways as a sum of consecutive naturals, for example, 81711 + ... + 82520.

Almost surely, 2^66513555 is an apocalyptic number.

66513555 is a deficient number, since it is larger than the sum of its proper divisors (52718877).

66513555 is a wasteful number, since it uses less digits than its factorization.

66513555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164248 (or 164239 counting only the distinct ones).

The product of its digits is 67500, while the sum is 36.

The square root of 66513555 is about 8155.5842831768. The cubic root of 66513555 is about 405.1694763961.

The spelling of 66513555 in words is "sixty-six million, five hundred thirteen thousand, five hundred fifty-five".