684991903454544 has 480 divisors, whose sum is σ = 2147968715203584. Its totient is φ = 184235853957120.

The previous prime is 684991903454533. The next prime is 684991903454549. The reversal of 684991903454544 is 445454309199486.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (684991903454549) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 13876601607 + ... + 13876650969.

Almost surely, 2^{684991903454544} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 684991903454544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1073984357601792).

684991903454544 is an abundant number, since it is smaller than the sum of its proper divisors (1462976811749040).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

684991903454544 is a wasteful number, since it uses less digits than its factorization.

684991903454544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50143 (or 50118 counting only the distinct ones).

The product of its (nonzero) digits is 2687385600, while the sum is 75.

The spelling of 684991903454544 in words is "six hundred eighty-four trillion, nine hundred ninety-one billion, nine hundred three million, four hundred fifty-four thousand, five hundred forty-four".