66431187108 has 72 divisors (see below), whose sum is σ = 197280510336. Its totient is φ = 18582148800.

The previous prime is 66431187107. The next prime is 66431187143. The reversal of 66431187108 is 80178113466.

It is not an unprimeable number, because it can be changed into a prime (66431187101) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6446988 + ... + 6457283.

It is an arithmetic number, because the mean of its divisors is an integer number (2740007088).

Almost surely, 2^66431187108 is an apocalyptic number.

It is an amenable number.

66431187108 is an abundant number, since it is smaller than the sum of its proper divisors (130849323228).

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

66431187108 is a wasteful number, since it uses less digits than its factorization.

66431187108 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12904305 (or 12904300 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 45.

The spelling of 66431187108 in words is "sixty-six billion, four hundred thirty-one million, one hundred eighty-seven thousand, one hundred eight".