66642646 has 12 divisors (see below), whose sum is σ = 116284788. Its totient is φ = 28561092.

The previous prime is 66642637. The next prime is 66642679. The reversal of 66642646 is 64624666.

It is a junction number, because it is equal to n+sod(n) for n = 66642599 and 66642608.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 339916 + ... + 340111.

It is an arithmetic number, because the mean of its divisors is an integer number (9690399).

Almost surely, 2^66642646 is an apocalyptic number.

66642646 is a deficient number, since it is larger than the sum of its proper divisors (49642142).

66642646 is a wasteful number, since it uses less digits than its factorization.

66642646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 680043 (or 680036 counting only the distinct ones).

The product of its digits is 248832, while the sum is 40.

The square root of 66642646 is about 8163.4947173377. The cubic root of 66642646 is about 405.4314276725.

The spelling of 66642646 in words is "sixty-six million, six hundred forty-two thousand, six hundred forty-six".