66661131 has 8 divisors (see below), whose sum is σ = 94109904. Its totient is φ = 41826560.

The previous prime is 66661109. The next prime is 66661151. The reversal of 66661131 is 13116666.

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

It is a cyclic number.

It is not a de Polignac number, because 66661131 - 2⁷ = 66661003 is a prime.

It is a super-2 number, since 2×66661131² = 8887412772398322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66661151) 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, 653490 + ... + 653591.

It is an arithmetic number, because the mean of its divisors is an integer number (11763738).

Almost surely, 2^66661131 is an apocalyptic number.

66661131 is a deficient number, since it is larger than the sum of its proper divisors (27448773).

66661131 is a wasteful number, since it uses less digits than its factorization.

66661131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1307101.

The product of its digits is 3888, while the sum is 30.

The square root of 66661131 is about 8164.6268132720. The cubic root of 66661131 is about 405.4689097133.

Adding to 66661131 its reverse (13116666), we get a palindrome (79777797).

The spelling of 66661131 in words is "sixty-six million, six hundred sixty-one thousand, one hundred thirty-one".