66438274140 has 192 divisors, whose sum is σ = 239553054720. Its totient is φ = 14971944960.

The previous prime is 66438274121. The next prime is 66438274163. The reversal of 66438274140 is 4147283466.

66438274140 is a `hidden beast` number, since 6 + 6 + 438 + 2 + 74 + 140 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 144604 + ... + 392156.

It is an arithmetic number, because the mean of its divisors is an integer number (1247672160).

Almost surely, 2^66438274140 is an apocalyptic number.

66438274140 is a gapful number since it is divisible by the number (60) 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 66438274140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (119776527360).

66438274140 is an abundant number, since it is smaller than the sum of its proper divisors (173114780580).

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

66438274140 is a wasteful number, since it uses less digits than its factorization.

66438274140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 247649 (or 247641 counting only the distinct ones).

The product of its (nonzero) digits is 774144, while the sum is 45.

The spelling of 66438274140 in words is "sixty-six billion, four hundred thirty-eight million, two hundred seventy-four thousand, one hundred forty".