66633331 has 4 divisors (see below), whose sum is σ = 66661272. Its totient is φ = 66605392.

The previous prime is 66633299. The next prime is 66633341. The reversal of 66633331 is 13333666.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13333666 = 2 ⋅6666833.

It is a cyclic number.

It is not a de Polignac number, because 66633331 - 2⁵ = 66633299 is a prime.

It is a super-2 number, since 2×66633331² = 8880001600311122, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 66633293 and 66633302.

It is not an unprimeable number, because it can be changed into a prime (66633341) 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, 10021 + ... + 15286.

It is an arithmetic number, because the mean of its divisors is an integer number (16665318).

Almost surely, 2^66633331 is an apocalyptic number.

66633331 is a deficient number, since it is larger than the sum of its proper divisors (27941).

66633331 is a wasteful number, since it uses less digits than its factorization.

66633331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27940.

The product of its digits is 17496, while the sum is 31.

The square root of 66633331 is about 8162.9241696833. The cubic root of 66633331 is about 405.4125370174.

Adding to 66633331 its reverse (13333666), we get a palindrome (79966997).

It can be divided in two parts, 6663 and 3331, that multiplied together give a triangular number (22194453 = T₆₆₆₂).

The spelling of 66633331 in words is "sixty-six million, six hundred thirty-three thousand, three hundred thirty-one".