684868899 has 32 divisors (see below), whose sum is σ = 1090430208. Its totient is φ = 376848000.

The previous prime is 684868897. The next prime is 684868937. The reversal of 684868899 is 998868486.

It is a Cunningham number, because it is equal to 26170²-1.

It is not a de Polignac number, because 684868899 - 2¹ = 684868897 is a prime.

It is not an unprimeable number, because it can be changed into a prime (684868897) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13084 + ... + 39254.

It is an arithmetic number, because the mean of its divisors is an integer number (34075944).

Almost surely, 2^684868899 is an apocalyptic number.

684868899 is a deficient number, since it is larger than the sum of its proper divisors (405561309).

684868899 is a wasteful number, since it uses less digits than its factorization.

684868899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26259.

The product of its digits is 47775744, while the sum is 66.

The square root of 684868899 is about 26169.9999808942. Note that the first 4 decimals coincide. The cubic root of 684868899 is about 881.4597410732.

The spelling of 684868899 in words is "six hundred eighty-four million, eight hundred sixty-eight thousand, eight hundred ninety-nine".