66557607 has 16 divisors (see below), whose sum is σ = 92825088. Its totient is φ = 42340320.

The previous prime is 66557597. The next prime is 66557609. The reversal of 66557607 is 70675566.

It is not a de Polignac number, because 66557607 - 2¹⁰ = 66556583 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66557609) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36438 + ... + 38220.

It is an arithmetic number, because the mean of its divisors is an integer number (5801568).

Almost surely, 2^66557607 is an apocalyptic number.

66557607 is a deficient number, since it is larger than the sum of its proper divisors (26267481).

66557607 is a wasteful number, since it uses less digits than its factorization.

66557607 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2350.

The product of its (nonzero) digits is 264600, while the sum is 42.

The square root of 66557607 is about 8158.2845623329. The cubic root of 66557607 is about 405.2589047182.

The spelling of 66557607 in words is "sixty-six million, five hundred fifty-seven thousand, six hundred seven".