66321331 has 2 divisors, whose sum is σ = 66321332. Its totient is φ = 66321330.

The previous prime is 66321323. The next prime is 66321373. The reversal of 66321331 is 13312366.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66321331 - 2³ = 66321323 is a prime.

It is a super-2 number, since 2×66321331² = 8797037891223122, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 66321296 and 66321305.

It is not a weakly prime, because it can be changed into another prime (66324331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33160665 + 33160666.

It is an arithmetic number, because the mean of its divisors is an integer number (33160666).

Almost surely, 2^66321331 is an apocalyptic number.

66321331 is a deficient number, since it is larger than the sum of its proper divisors (1).

66321331 is an equidigital number, since it uses as much as digits as its factorization.

66321331 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1944, while the sum is 25.

The square root of 66321331 is about 8143.7909477098. The cubic root of 66321331 is about 404.7787868811.

Adding to 66321331 its reverse (13312366), we get a palindrome (79633697).

The spelling of 66321331 in words is "sixty-six million, three hundred twenty-one thousand, three hundred thirty-one".