66615516588 has 18 divisors (see below), whose sum is σ = 155438291596. Its totient is φ = 22204874168.

The previous prime is 66615516563. The next prime is 66615516641. The reversal of 66615516588 is 88561551666.

It is a super-2 number, since 2×66615516588² (a number of 22 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 856831 + ... + 931337.

Almost surely, 2^66615516588 is an apocalyptic number.

It is an amenable number.

66615516588 is an abundant number, since it is smaller than the sum of its proper divisors (88822775008).

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

66615516588 is an frugal number, since it uses more digits than its factorization.

66615516588 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149021 (or 74512 counting only the distinct ones).

The product of its digits is 10368000, while the sum is 57.

It can be divided in two parts, 6661551658 and 8, that added together give a palindrome (6661551666).

The spelling of 66615516588 in words is "sixty-six billion, six hundred fifteen million, five hundred sixteen thousand, five hundred eighty-eight".