66654331 has 4 divisors (see below), whose sum is σ = 70575192. Its totient is φ = 62733472.

The previous prime is 66654323. The next prime is 66654373. The reversal of 66654331 is 13345666.

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 66654331 - 2³ = 66654323 is a prime.

It is a super-2 number, since 2×66654331² = 8885599682115122, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (66651331) 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, 1960405 + ... + 1960438.

It is an arithmetic number, because the mean of its divisors is an integer number (17643798).

Almost surely, 2^66654331 is an apocalyptic number.

66654331 is the 5164-th centered pentagonal number.

66654331 is a deficient number, since it is larger than the sum of its proper divisors (3920861).

66654331 is a wasteful number, since it uses less digits than its factorization.

66654331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3920860.

The product of its digits is 38880, while the sum is 34.

The square root of 66654331 is about 8164.2103721058. The cubic root of 66654331 is about 405.4551221567.

Adding to 66654331 its reverse (13345666), we get a palindrome (79999997).

The spelling of 66654331 in words is "sixty-six million, six hundred fifty-four thousand, three hundred thirty-one".