66478044654 has 128 divisors (see below), whose sum is σ = 172696043520. Its totient is φ = 18560428128.

The previous prime is 66478044649. The next prime is 66478044679. The reversal of 66478044654 is 45644087466.

It is a happy number.

66478044654 is a `hidden beast` number, since 66 + 47 + 80 + 4 + 465 + 4 = 666.

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

It is a self number, because there is not a number n which added to its sum of digits gives 66478044654.

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, 12913309 + ... + 12918455.

It is an arithmetic number, because the mean of its divisors is an integer number (1349187840).

Almost surely, 2^66478044654 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66478044654, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86348021760).

66478044654 is an abundant number, since it is smaller than the sum of its proper divisors (106217998866).

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

66478044654 is a wasteful number, since it uses less digits than its factorization.

66478044654 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5939 (or 5933 counting only the distinct ones).

The product of its (nonzero) digits is 15482880, while the sum is 54.

The spelling of 66478044654 in words is "sixty-six billion, four hundred seventy-eight million, forty-four thousand, six hundred fifty-four".