66437081 has 4 divisors (see below), whose sum is σ = 67347252. Its totient is φ = 65526912.

The previous prime is 66437069. The next prime is 66437083. The reversal of 66437081 is 18073466.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18073466 = 2 ⋅9036733.

It can be written as a sum of positive squares in 2 ways, for example, as 43349056 + 23088025 = 6584^2 + 4805^2 .

It is a cyclic number.

It is not a de Polignac number, because 66437081 - 2¹⁰ = 66436057 is a prime.

It is a super-2 number, since 2×66437081² = 8827771463601122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66437083) 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, 454976 + ... + 455121.

It is an arithmetic number, because the mean of its divisors is an integer number (16836813).

Almost surely, 2^66437081 is an apocalyptic number.

It is an amenable number.

66437081 is a deficient number, since it is larger than the sum of its proper divisors (910171).

66437081 is an equidigital number, since it uses as much as digits as its factorization.

66437081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 910170.

The product of its (nonzero) digits is 24192, while the sum is 35.

The square root of 66437081 is about 8150.8944907906. The cubic root of 66437081 is about 405.0141355631.

The spelling of 66437081 in words is "sixty-six million, four hundred thirty-seven thousand, eighty-one".