66806311005 has 64 divisors (see below), whose sum is σ = 135770534400. Its totient is φ = 30531686400.

The previous prime is 66806311003. The next prime is 66806311007. The reversal of 66806311005 is 50011360866.

It is a happy number.

66806311005 is a `hidden beast` number, since 6 + 6 + 8 + 0 + 631 + 10 + 0 + 5 = 666.

It is an interprime number because it is at equal distance from previous prime (66806311003) and next prime (66806311007).

It is not a de Polignac number, because 66806311005 - 2¹ = 66806311003 is a prime.

It is a super-2 number, since 2×66806311005² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66806311003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 4631805 + ... + 4646205.

It is an arithmetic number, because the mean of its divisors is an integer number (2121414600).

Almost surely, 2^66806311005 is an apocalyptic number.

It is an amenable number.

66806311005 is an abundant number, since it is smaller than the sum of its proper divisors (68964223395).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66806311005 is a wasteful number, since it uses less digits than its factorization.

66806311005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19331 (or 19325 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The spelling of 66806311005 in words is "sixty-six billion, eight hundred six million, three hundred eleven thousand, five".