66131869 has 8 divisors (see below), whose sum is σ = 67436408. Its totient is φ = 64834560.

The previous prime is 66131843. The next prime is 66131873. The reversal of 66131869 is 96813166.

It can be written as a sum of positive squares in 4 ways, for example, as 2722500 + 63409369 = 1650^2 + 7963^2 .

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 66131869 - 2¹¹ = 66129821 is a prime.

It is a super-2 number, since 2×66131869² = 8746848194866322, 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 (66131899) 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, 18949 + ... + 22165.

It is an arithmetic number, because the mean of its divisors is an integer number (8429551).

Almost surely, 2^66131869 is an apocalyptic number.

It is an amenable number.

66131869 is a deficient number, since it is larger than the sum of its proper divisors (1304539).

66131869 is a wasteful number, since it uses less digits than its factorization.

66131869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3615.

The product of its digits is 46656, while the sum is 40.

The square root of 66131869 is about 8132.1503306321. The cubic root of 66131869 is about 404.3929716330.

The spelling of 66131869 in words is "sixty-six million, one hundred thirty-one thousand, eight hundred sixty-nine".