66826321919 has 4 divisors (see below), whose sum is σ = 76372939344. Its totient is φ = 57279704496.

The previous prime is 66826321901. The next prime is 66826321927. The reversal of 66826321919 is 91912362866.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 91912362866 = 2 ⋅45956181433.

It is not a de Polignac number, because 66826321919 - 2²⁸ = 66557886463 is a prime.

It is a super-2 number, since 2×66826321919² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66826321949) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4773308702 + ... + 4773308715.

It is an arithmetic number, because the mean of its divisors is an integer number (19093234836).

Almost surely, 2^66826321919 is an apocalyptic number.

66826321919 is a deficient number, since it is larger than the sum of its proper divisors (9546617425).

66826321919 is an equidigital number, since it uses as much as digits as its factorization.

66826321919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9546617424.

The product of its digits is 1679616, while the sum is 53.

The spelling of 66826321919 in words is "sixty-six billion, eight hundred twenty-six million, three hundred twenty-one thousand, nine hundred nineteen".