66311601 has 4 divisors (see below), whose sum is σ = 88415472. Its totient is φ = 44207732.

The previous prime is 66311591. The next prime is 66311621. The reversal of 66311601 is 10611366.

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 66311601 - 2⁵ = 66311569 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66311621) 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, 11051931 + ... + 11051936.

It is an arithmetic number, because the mean of its divisors is an integer number (22103868).

Almost surely, 2^66311601 is an apocalyptic number.

It is an amenable number.

66311601 is a deficient number, since it is larger than the sum of its proper divisors (22103871).

66311601 is a wasteful number, since it uses less digits than its factorization.

66311601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22103870.

The product of its (nonzero) digits is 648, while the sum is 24.

The square root of 66311601 is about 8143.1935381643. The cubic root of 66311601 is about 404.7589908860.

Adding to 66311601 its reverse (10611366), we get a palindrome (76922967).

The spelling of 66311601 in words is "sixty-six million, three hundred eleven thousand, six hundred one".