66826321921 has 16 divisors (see below), whose sum is σ = 71159482368. Its totient is φ = 62538150400.

The previous prime is 66826321901. The next prime is 66826321927. The reversal of 66826321921 is 12912362866.

It is a cyclic number.

It is not a de Polignac number, because 66826321921 - 2³³ = 58236387329 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66826321927) 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, 12598956 + ... + 12604258.

It is an arithmetic number, because the mean of its divisors is an integer number (4447467648).

Almost surely, 2^66826321921 is an apocalyptic number.

It is an amenable number.

66826321921 is a deficient number, since it is larger than the sum of its proper divisors (4333160447).

66826321921 is a wasteful number, since it uses less digits than its factorization.

66826321921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9392.

The product of its digits is 373248, while the sum is 46.

The spelling of 66826321921 in words is "sixty-six billion, eight hundred twenty-six million, three hundred twenty-one thousand, nine hundred twenty-one".