66321231 has 16 divisors (see below), whose sum is σ = 93713760. Its totient is φ = 41646080.

The previous prime is 66321217. The next prime is 66321271. The reversal of 66321231 is 13212366.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 66321231 - 2¹⁰ = 66320207 is a prime.

It is a super-2 number, since 2×66321231² = 8797011362710722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66321271) 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, 5730 + ... + 12863.

It is an arithmetic number, because the mean of its divisors is an integer number (5857110).

Almost surely, 2^66321231 is an apocalyptic number.

66321231 is a deficient number, since it is larger than the sum of its proper divisors (27392529).

66321231 is a wasteful number, since it uses less digits than its factorization.

66321231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18666.

The product of its digits is 1296, while the sum is 24.

The square root of 66321231 is about 8143.7848080607. The cubic root of 66321231 is about 404.7785834377.

Adding to 66321231 its reverse (13212366), we get a palindrome (79533597).

The spelling of 66321231 in words is "sixty-six million, three hundred twenty-one thousand, two hundred thirty-one".