684039091 has 4 divisors (see below), whose sum is σ = 702526672. Its totient is φ = 665551512.

The previous prime is 684039079. The next prime is 684039101. The reversal of 684039091 is 190930486.

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

It is a cyclic number.

It is not a de Polignac number, because 684039091 - 2²⁹ = 147168179 is a prime.

It is a super-2 number, since 2×684039091² = 935818956032212562, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (684039061) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9243735 + ... + 9243808.

It is an arithmetic number, because the mean of its divisors is an integer number (175631668).

Almost surely, 2^684039091 is an apocalyptic number.

684039091 is a deficient number, since it is larger than the sum of its proper divisors (18487581).

684039091 is a wasteful number, since it uses less digits than its factorization.

684039091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18487580.

The product of its (nonzero) digits is 46656, while the sum is 40.

The square root of 684039091 is about 26154.1409914377. The cubic root of 684039091 is about 881.1035960468.

The spelling of 684039091 in words is "six hundred eighty-four million, thirty-nine thousand, ninety-one".