66520231 has 8 divisors (see below), whose sum is σ = 67100544. Its totient is φ = 65942880.

The previous prime is 66520219. The next prime is 66520243. The reversal of 66520231 is 13202566.

It is an interprime number because it is at equal distance from previous prime (66520219) and next prime (66520243).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66520231 is a prime.

It is a super-2 number, since 2×66520231² = 8849882264586722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66520196 and 66520205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66520211) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 70221 + ... + 71161.

It is an arithmetic number, because the mean of its divisors is an integer number (8387568).

Almost surely, 2^66520231 is an apocalyptic number.

66520231 is a deficient number, since it is larger than the sum of its proper divisors (580313).

66520231 is a wasteful number, since it uses less digits than its factorization.

66520231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1481.

The product of its (nonzero) digits is 2160, while the sum is 25.

The square root of 66520231 is about 8155.9935630185. The cubic root of 66520231 is about 405.1830316327.

Adding to 66520231 its reverse (13202566), we get a palindrome (79722797).

The spelling of 66520231 in words is "sixty-six million, five hundred twenty thousand, two hundred thirty-one".