66443540164 has 6 divisors (see below), whose sum is σ = 116276195294. Its totient is φ = 33221770080.

The previous prime is 66443540161. The next prime is 66443540237. The reversal of 66443540164 is 46104534466.

It can be written as a sum of positive squares in only one way, i.e., 66043860100 + 399680064 = 256990^2 + 19992^2 .

It is a super-2 number, since 2×66443540164² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 66443540164.

It is not an unprimeable number, because it can be changed into a prime (66443540161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8305442517 + ... + 8305442524.

Almost surely, 2^66443540164 is an apocalyptic number.

It is an amenable number.

66443540164 is a deficient number, since it is larger than the sum of its proper divisors (49832655130).

66443540164 is a wasteful number, since it uses less digits than its factorization.

66443540164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16610885045 (or 16610885043 counting only the distinct ones).

The product of its (nonzero) digits is 829440, while the sum is 43.

The spelling of 66443540164 in words is "sixty-six billion, four hundred forty-three million, five hundred forty thousand, one hundred sixty-four".