66188881984 has 21 divisors (see below), whose sum is σ = 131347647007. Its totient is φ = 33093411904.

The previous prime is 66188881961. The next prime is 66188881991. The reversal of 66188881984 is 48918888166.

The square root of 66188881984 is 257272.

It is a perfect power (a square), and thus also a powerful number.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 2042097 + ... + 2074255.

Almost surely, 2^66188881984 is an apocalyptic number.

66188881984 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

66188881984 is the 257272-nd square number.

It is an amenable number.

66188881984 is a deficient number, since it is larger than the sum of its proper divisors (65158765023).

66188881984 is an frugal number, since it uses more digits than its factorization.

66188881984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64330 (or 32161 counting only the distinct ones).

The product of its digits is 42467328, while the sum is 67.

The spelling of 66188881984 in words is "sixty-six billion, one hundred eighty-eight million, eight hundred eighty-one thousand, nine hundred eighty-four".