840016666 has 4 divisors (see below), whose sum is σ = 1260025002. Its totient is φ = 420008332.

The previous prime is 840016637. The next prime is 840016673. The reversal of 840016666 is 666610048.

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

It can be written as a sum of positive squares in only one way, i.e., 553425625 + 286591041 = 23525^2 + 16929^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210004165 + ... + 210004168.

Almost surely, 2^840016666 is an apocalyptic number.

840016666 is a deficient number, since it is larger than the sum of its proper divisors (420008336).

840016666 is a wasteful number, since it uses less digits than its factorization.

840016666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 420008335.

The product of its (nonzero) digits is 41472, while the sum is 37.

The square root of 840016666 is about 28983.0410067681. The cubic root of 840016666 is about 943.5450361084.

The spelling of 840016666 in words is "eight hundred forty million, sixteen thousand, six hundred sixty-six".