66440347545600 has 4992 divisors, whose sum is σ = 307088238428160. Its totient is φ = 13759414272000.

The previous prime is 66440347545491. The next prime is 66440347545617. The reversal of 66440347545600 is 654574304466.

It is a happy number.

66440347545600 is a `hidden beast` number, since 6 + 6 + 4 + 4 + 0 + 3 + 4 + 75 + 4 + 560 + 0 = 666.

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 383 ways as a sum of consecutive naturals, for example, 910141747164 + ... + 910141747236.

Almost surely, 2^{66440347545600} is an apocalyptic number.

66440347545600 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 66440347545600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (153544119214080).

66440347545600 is an abundant number, since it is smaller than the sum of its proper divisors (240647890882560).

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

66440347545600 is a wasteful number, since it uses less digits than its factorization.

66440347545600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 232 (or 199 counting only the distinct ones).

The product of its (nonzero) digits is 29030400, while the sum is 54.

The spelling of 66440347545600 in words is "sixty-six trillion, four hundred forty billion, three hundred forty-seven million, five hundred forty-five thousand, six hundred".