66432881 has 4 divisors (see below), whose sum is σ = 68723700. Its totient is φ = 64142064.

The previous prime is 66432827. The next prime is 66432887. The reversal of 66432881 is 18823466.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 20070400 + 46362481 = 4480^2 + 6809^2 .

It is a cyclic number.

It is not a de Polignac number, because 66432881 - 2¹⁰ = 66431857 is a prime.

It is a super-2 number, since 2×66432881² = 8826655355920322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66432887) 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, 1145366 + ... + 1145423.

It is an arithmetic number, because the mean of its divisors is an integer number (17180925).

Almost surely, 2^66432881 is an apocalyptic number.

It is an amenable number.

66432881 is a deficient number, since it is larger than the sum of its proper divisors (2290819).

66432881 is a wasteful number, since it uses less digits than its factorization.

66432881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2290818.

The product of its digits is 55296, while the sum is 38.

The square root of 66432881 is about 8150.6368462839. The cubic root of 66432881 is about 405.0056006948.

The spelling of 66432881 in words is "sixty-six million, four hundred thirty-two thousand, eight hundred eighty-one".