66826167421 has 24 divisors (see below), whose sum is σ = 74442542184. Its totient is φ = 59917777920.

The previous prime is 66826167413. The next prime is 66826167511. The reversal of 66826167421 is 12476162866.

It can be written as a sum of positive squares in 12 ways, for example, as 45973363396 + 20852804025 = 214414^2 + 144405^2 .

It is not a de Polignac number, because 66826167421 - 2³ = 66826167413 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66826161421) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3849441 + ... + 3866761.

It is an arithmetic number, because the mean of its divisors is an integer number (3101772591).

Almost surely, 2^66826167421 is an apocalyptic number.

It is an amenable number.

66826167421 is a deficient number, since it is larger than the sum of its proper divisors (7616374763).

66826167421 is a wasteful number, since it uses less digits than its factorization.

66826167421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18001 (or 17988 counting only the distinct ones).

The product of its digits is 1161216, while the sum is 49.

The spelling of 66826167421 in words is "sixty-six billion, eight hundred twenty-six million, one hundred sixty-seven thousand, four hundred twenty-one".