66442646 has 4 divisors (see below), whose sum is σ = 99663972. Its totient is φ = 33221322.

The previous prime is 66442637. The next prime is 66442657. The reversal of 66442646 is 64624466.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16610660 + ... + 16610663.

It is an arithmetic number, because the mean of its divisors is an integer number (24915993).

Almost surely, 2^66442646 is an apocalyptic number.

66442646 is a deficient number, since it is larger than the sum of its proper divisors (33221326).

66442646 is a wasteful number, since it uses less digits than its factorization.

66442646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33221325.

The product of its digits is 165888, while the sum is 38.

The square root of 66442646 is about 8151.2358572182. The cubic root of 66442646 is about 405.0254437096.

The spelling of 66442646 in words is "sixty-six million, four hundred forty-two thousand, six hundred forty-six".