66111988536 has 256 divisors, whose sum is σ = 211405824000. Its totient is φ = 18932538240.

The previous prime is 66111988487. The next prime is 66111988541. The reversal of 66111988536 is 63588911166.

66111988536 is a `hidden beast` number, since 6 + 6 + 1 + 11 + 98 + 8 + 536 = 666.

66111988536 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 20900091 + ... + 20903253.

It is an arithmetic number, because the mean of its divisors is an integer number (825804000).

Almost surely, 2^66111988536 is an apocalyptic number.

66111988536 is a gapful number since it is divisible by the number (66) 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 66111988536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (105702912000).

66111988536 is an abundant number, since it is smaller than the sum of its proper divisors (145293835464).

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

66111988536 is a wasteful number, since it uses less digits than its factorization.

66111988536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3671 (or 3661 counting only the distinct ones).

The product of its digits is 1866240, while the sum is 54.

The spelling of 66111988536 in words is "sixty-six billion, one hundred eleven million, nine hundred eighty-eight thousand, five hundred thirty-six".