66642443 has 16 divisors (see below), whose sum is σ = 81150720. Its totient is φ = 53454816.

The previous prime is 66642437. The next prime is 66642469. The reversal of 66642443 is 34424666.

It is a cyclic number.

It is not a de Polignac number, because 66642443 - 2⁶ = 66642379 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66642473) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8021 + ... + 14057.

It is an arithmetic number, because the mean of its divisors is an integer number (5071920).

Almost surely, 2^66642443 is an apocalyptic number.

66642443 is a deficient number, since it is larger than the sum of its proper divisors (14508277).

66642443 is a wasteful number, since it uses less digits than its factorization.

66642443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6146.

The product of its digits is 82944, while the sum is 35.

The square root of 66642443 is about 8163.4822839276. The cubic root of 66642443 is about 405.4310160109.

The spelling of 66642443 in words is "sixty-six million, six hundred forty-two thousand, four hundred forty-three".