66556967 has 4 divisors (see below), whose sum is σ = 66581736. Its totient is φ = 66532200.

The previous prime is 66556961. The next prime is 66556999. The reversal of 66556967 is 76965566.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66556967 - 2⁴ = 66556951 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66556961) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7784 + ... + 13917.

It is an arithmetic number, because the mean of its divisors is an integer number (16645434).

Almost surely, 2^66556967 is an apocalyptic number.

66556967 is a deficient number, since it is larger than the sum of its proper divisors (24769).

66556967 is a wasteful number, since it uses less digits than its factorization.

66556967 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24768.

The product of its digits is 2041200, while the sum is 50.

The square root of 66556967 is about 8158.2453383065. The cubic root of 66556967 is about 405.2576057605.

The spelling of 66556967 in words is "sixty-six million, five hundred fifty-six thousand, nine hundred sixty-seven".