66231231 has 16 divisors (see below), whose sum is σ = 96844800. Its totient is φ = 39928320.

The previous prime is 66231229. The next prime is 66231233. The reversal of 66231231 is 13213266.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (66231229) and next prime (66231233).

It is not a de Polignac number, because 66231231 - 2¹ = 66231229 is a prime.

It is a super-2 number, since 2×66231231² = 8773151919550722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66231233) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1170 + ... + 11568.

It is an arithmetic number, because the mean of its divisors is an integer number (6052800).

Almost surely, 2^66231231 is an apocalyptic number.

66231231 is a deficient number, since it is larger than the sum of its proper divisors (30613569).

66231231 is a wasteful number, since it uses less digits than its factorization.

66231231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10606.

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

The square root of 66231231 is about 8138.2572458727. The cubic root of 66231231 is about 404.5954014546.

Adding to 66231231 its reverse (13213266), we get a palindrome (79444497).

The spelling of 66231231 in words is "sixty-six million, two hundred thirty-one thousand, two hundred thirty-one".