66137803776 has 528 divisors, whose sum is σ = 219669760128. Its totient is φ = 19707494400.

The previous prime is 66137803769. The next prime is 66137803789. The reversal of 66137803776 is 67730873166.

It is a happy number.

66137803776 is a `hidden beast` number, since 66 + 137 + 80 + 377 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (528).

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

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

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, 199811931 + ... + 199812261.

Almost surely, 2^66137803776 is an apocalyptic number.

66137803776 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 66137803776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (109834880064).

66137803776 is an abundant number, since it is smaller than the sum of its proper divisors (153531956352).

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

66137803776 is a wasteful number, since it uses less digits than its factorization.

66137803776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 450 (or 420 counting only the distinct ones).

The product of its (nonzero) digits is 5334336, while the sum is 54.

The spelling of 66137803776 in words is "sixty-six billion, one hundred thirty-seven million, eight hundred three thousand, seven hundred seventy-six".