66865438180 has 24 divisors (see below), whose sum is σ = 140431951800. Its totient is φ = 26743407360.

The previous prime is 66865438163. The next prime is 66865438181. The reversal of 66865438180 is 8183456866.

It can be written as a sum of positive squares in 4 ways, for example, as 14702532516 + 52162905664 = 121254^2 + 228392^2 .

It is a hoax number, since the sum of its digits (55) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (66865438181) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30960 + ... + 367000.

It is an arithmetic number, because the mean of its divisors is an integer number (5851331325).

Almost surely, 2^66865438180 is an apocalyptic number.

It is an amenable number.

66865438180 is an abundant number, since it is smaller than the sum of its proper divisors (73566513620).

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

66865438180 is a wasteful number, since it uses less digits than its factorization.

66865438180 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 345999 (or 345997 counting only the distinct ones).

The product of its (nonzero) digits is 6635520, while the sum is 55.

The spelling of 66865438180 in words is "sixty-six billion, eight hundred sixty-five million, four hundred thirty-eight thousand, one hundred eighty".