66621335611 has 4 divisors (see below), whose sum is σ = 66623034952. Its totient is φ = 66619636272.

The previous prime is 66621335593. The next prime is 66621335639. The reversal of 66621335611 is 11653312666.

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 66621335611 - 2²¹ = 66619238459 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66621335111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 789441 + ... + 869746.

It is an arithmetic number, because the mean of its divisors is an integer number (16655758738).

Almost surely, 2^66621335611 is an apocalyptic number.

66621335611 is a deficient number, since it is larger than the sum of its proper divisors (1699341).

66621335611 is a wasteful number, since it uses less digits than its factorization.

66621335611 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1699340.

The product of its digits is 116640, while the sum is 40.

The spelling of 66621335611 in words is "sixty-six billion, six hundred twenty-one million, three hundred thirty-five thousand, six hundred eleven".