66653231616 has 320 divisors, whose sum is σ = 210938999040. Its totient is φ = 20729364480.

The previous prime is 66653231597. The next prime is 66653231633. The reversal of 66653231616 is 61613235666.

It is a super-2 number, since 2×66653231616² (a number of 22 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13033476 + ... + 13038588.

It is an arithmetic number, because the mean of its divisors is an integer number (659184372).

Almost surely, 2^66653231616 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66653231616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (105469499520).

66653231616 is an abundant number, since it is smaller than the sum of its proper divisors (144285767424).

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

66653231616 is a wasteful number, since it uses less digits than its factorization.

66653231616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5204 (or 5182 counting only the distinct ones).

The product of its digits is 699840, while the sum is 45.

The spelling of 66653231616 in words is "sixty-six billion, six hundred fifty-three million, two hundred thirty-one thousand, six hundred sixteen".