66617898624 has 96 divisors (see below), whose sum is σ = 192523464900. Its totient is φ = 22110572544.

The previous prime is 66617898583. The next prime is 66617898643. The reversal of 66617898624 is 42689871666.

It can be written as a sum of positive squares in 2 ways, for example, as 57888360000 + 8729538624 = 240600^2 + 93432^2 .

It is a tau number, because it is divible by the number of its divisors (96).

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 11 ways as a sum of consecutive naturals, for example, 144322 + ... + 392510.

Almost surely, 2^66617898624 is an apocalyptic number.

66617898624 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66617898624, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (96261732450).

66617898624 is an abundant number, since it is smaller than the sum of its proper divisors (125905566276).

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

66617898624 is a wasteful number, since it uses less digits than its factorization.

66617898624 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 248442 (or 248427 counting only the distinct ones).

The product of its digits is 41803776, while the sum is 63.

The spelling of 66617898624 in words is "sixty-six billion, six hundred seventeen million, eight hundred ninety-eight thousand, six hundred twenty-four".