66239231 has 4 divisors (see below), whose sum is σ = 67854864. Its totient is φ = 64623600.

The previous prime is 66239207. The next prime is 66239249. The reversal of 66239231 is 13293266.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66239231 - 2⁶ = 66239167 is a prime.

It is a super-2 number, since 2×66239231² = 8775271446942722, which 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 (66233231) 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, 807755 + ... + 807836.

It is an arithmetic number, because the mean of its divisors is an integer number (16963716).

Almost surely, 2^66239231 is an apocalyptic number.

66239231 is a deficient number, since it is larger than the sum of its proper divisors (1615633).

66239231 is a wasteful number, since it uses less digits than its factorization.

66239231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1615632.

The product of its digits is 11664, while the sum is 32.

The square root of 66239231 is about 8138.7487367531. The cubic root of 66239231 is about 404.6116910149.

It can be divided in two parts, 662 and 39231, that added together give a palindrome (39893).

The spelling of 66239231 in words is "sixty-six million, two hundred thirty-nine thousand, two hundred thirty-one".