66889784 has 32 divisors (see below), whose sum is σ = 138724320. Its totient is φ = 30036096.

The previous prime is 66889777. The next prime is 66889793. The reversal of 66889784 is 48798866.

It is a congruent number.

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, 4844 + ... + 12539.

It is an arithmetic number, because the mean of its divisors is an integer number (4335135).

Almost surely, 2^66889784 is an apocalyptic number.

It is an amenable number.

66889784 is an abundant number, since it is smaller than the sum of its proper divisors (71834536).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66889784 is a wasteful number, since it uses less digits than its factorization.

66889784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17439 (or 17435 counting only the distinct ones).

The product of its digits is 4644864, while the sum is 56.

The square root of 66889784 is about 8178.6174870818. The cubic root of 66889784 is about 405.9319775708.

The spelling of 66889784 in words is "sixty-six million, eight hundred eighty-nine thousand, seven hundred eighty-four".