66649859136 has 336 divisors, whose sum is σ = 229649292288. Its totient is φ = 18079027200.

The previous prime is 66649859119. The next prime is 66649859141. The reversal of 66649859136 is 63195894666.

It is a tau number, because it is divible by the number of its divisors (336).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6619546 + ... + 6629606.

Almost surely, 2^66649859136 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 66649859136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (114824646144).

66649859136 is an abundant number, since it is smaller than the sum of its proper divisors (162999433152).

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

66649859136 is a wasteful number, since it uses less digits than its factorization.

66649859136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10170 (or 10157 counting only the distinct ones).

The product of its digits is 50388480, while the sum is 63.

The spelling of 66649859136 in words is "sixty-six billion, six hundred forty-nine million, eight hundred fifty-nine thousand, one hundred thirty-six".