684909716989 has 4 divisors (see below), whose sum is σ = 696518356320. Its totient is φ = 673301077660.

The previous prime is 684909716957. The next prime is 684909716999. The reversal of 684909716989 is 989617909486.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 684909716989 - 2⁵ = 684909716957 is a prime.

It is a super-2 number, since 2×684909716989² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (684909716929) 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, 5804319577 + ... + 5804319694.

It is an arithmetic number, because the mean of its divisors is an integer number (174129589080).

Almost surely, 2^684909716989 is an apocalyptic number.

It is an amenable number.

684909716989 is a deficient number, since it is larger than the sum of its proper divisors (11608639331).

684909716989 is a wasteful number, since it uses less digits than its factorization.

684909716989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11608639330.

The product of its (nonzero) digits is 423263232, while the sum is 76.

The spelling of 684909716989 in words is "six hundred eighty-four billion, nine hundred nine million, seven hundred sixteen thousand, nine hundred eighty-nine".