66997553478 has 8 divisors (see below), whose sum is σ = 133995106968. Its totient is φ = 22332517824.

The previous prime is 66997553471. The next prime is 66997553479. The reversal of 66997553478 is 87435579966.

It is a sphenic number, since it is the product of 3 distinct primes.

66997553478 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66997553471) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 5583129451 + ... + 5583129462.

It is an arithmetic number, because the mean of its divisors is an integer number (16749388371).

Almost surely, 2^66997553478 is an apocalyptic number.

66997553478 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

66997553478 is a wasteful number, since it uses less digits than its factorization.

66997553478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11166258918.

The product of its digits is 342921600, while the sum is 69.

The spelling of 66997553478 in words is "sixty-six billion, nine hundred ninety-seven million, five hundred fifty-three thousand, four hundred seventy-eight".