66943091021 has 8 divisors (see below), whose sum is σ = 70128076800. Its totient is φ = 63816545520.

The previous prime is 66943090961. The next prime is 66943091029. The reversal of 66943091021 is 12019034966.

66943091021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66943091021 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66943091021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66943091029) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14607725 + ... + 14612306.

It is an arithmetic number, because the mean of its divisors is an integer number (8766009600).

Almost surely, 2^66943091021 is an apocalyptic number.

It is an amenable number.

66943091021 is a deficient number, since it is larger than the sum of its proper divisors (3184985779).

66943091021 is a wasteful number, since it uses less digits than its factorization.

66943091021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29220139.

The product of its (nonzero) digits is 69984, while the sum is 41.

The spelling of 66943091021 in words is "sixty-six billion, nine hundred forty-three million, ninety-one thousand, twenty-one".