684868901 has 4 divisors (see below), whose sum is σ = 708485100. Its totient is φ = 661252704.

The previous prime is 684868897. The next prime is 684868937. The reversal of 684868901 is 109868486.

It is a happy number.

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

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 359102500 + 325766401 = 18950^2 + 18049^2 .

It is a cyclic number.

It is not a de Polignac number, because 684868901 - 2² = 684868897 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 684868901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (684858901) 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, 11808056 + ... + 11808113.

It is an arithmetic number, because the mean of its divisors is an integer number (177121275).

Almost surely, 2^684868901 is an apocalyptic number.

It is an amenable number.

684868901 is a deficient number, since it is larger than the sum of its proper divisors (23616199).

684868901 is a wasteful number, since it uses less digits than its factorization.

684868901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23616198.

The product of its (nonzero) digits is 663552, while the sum is 50.

The square root of 684868901 is about 26170.0000191058. Note that the first 4 decimals coincide. The cubic root of 684868901 is about 881.4597419313.

The spelling of 684868901 in words is "six hundred eighty-four million, eight hundred sixty-eight thousand, nine hundred one".