66654001680 has 80 divisors (see below), whose sum is σ = 236145611904. Its totient is φ = 15235200000.

The previous prime is 66654001651. The next prime is 66654001681. The reversal of 66654001680 is 8610045666.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (66654001681) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19835821 + ... + 19839180.

Almost surely, 2^66654001680 is an apocalyptic number.

66654001680 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66654001680 is an abundant number, since it is smaller than the sum of its proper divisors (169491610224).

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

66654001680 is a wasteful number, since it uses less digits than its factorization.

66654001680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39675024 (or 39675018 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 42.

The spelling of 66654001680 in words is "sixty-six billion, six hundred fifty-four million, one thousand, six hundred eighty".