66601601 has 4 divisors (see below), whose sum is σ = 72656304. Its totient is φ = 60546900.

The previous prime is 66601567. The next prime is 66601643. The reversal of 66601601 is 10610666.

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.

It is a cyclic number.

It is not a de Polignac number, because 66601601 - 2²² = 62407297 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66601681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3027335 + ... + 3027356.

It is an arithmetic number, because the mean of its divisors is an integer number (18164076).

Almost surely, 2^66601601 is an apocalyptic number.

It is an amenable number.

66601601 is a deficient number, since it is larger than the sum of its proper divisors (6054703).

66601601 is a wasteful number, since it uses less digits than its factorization.

66601601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6054702.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 66601601 is about 8160.9803945359. The cubic root of 66601601 is about 405.3481759236.

The spelling of 66601601 in words is "sixty-six million, six hundred one thousand, six hundred one".