66809642 has 16 divisors (see below), whose sum is σ = 103289472. Its totient is φ = 32386320.

The previous prime is 66809599. The next prime is 66809671. The reversal of 66809642 is 24690866.

It is a self number, because there is not a number n which added to its sum of digits gives 66809642.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21563 + ... + 24465.

It is an arithmetic number, because the mean of its divisors is an integer number (6455592).

Almost surely, 2^66809642 is an apocalyptic number.

66809642 is a deficient number, since it is larger than the sum of its proper divisors (36479830).

66809642 is a wasteful number, since it uses less digits than its factorization.

66809642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3253.

The product of its (nonzero) digits is 124416, while the sum is 41.

The square root of 66809642 is about 8173.7165353345. The cubic root of 66809642 is about 405.7697943506.

The spelling of 66809642 in words is "sixty-six million, eight hundred nine thousand, six hundred forty-two".