684912913 has 4 divisors (see below), whose sum is σ = 701618148. Its totient is φ = 668207680.

The previous prime is 684912911. The next prime is 684912947. The reversal of 684912913 is 319219486.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 270668304 + 414244609 = 16452^2 + 20353^2 .

It is a cyclic number.

It is not a de Polignac number, because 684912913 - 2¹ = 684912911 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 684912913.

It is not an unprimeable number, because it can be changed into a prime (684912911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8352556 + ... + 8352637.

It is an arithmetic number, because the mean of its divisors is an integer number (175404537).

Almost surely, 2^684912913 is an apocalyptic number.

It is an amenable number.

684912913 is a deficient number, since it is larger than the sum of its proper divisors (16705235).

684912913 is a wasteful number, since it uses less digits than its factorization.

684912913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16705234.

The product of its digits is 93312, while the sum is 43.

The square root of 684912913 is about 26170.8408921074. The cubic root of 684912913 is about 881.4786233917.

The spelling of 684912913 in words is "six hundred eighty-four million, nine hundred twelve thousand, nine hundred thirteen".