684689251128 has 64 divisors (see below), whose sum is σ = 1721888409600. Its totient is φ = 226874797440.

The previous prime is 684689251123. The next prime is 684689251177. The reversal of 684689251128 is 821152986486.

It is a super-2 number, since 2×684689251128² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (684689251121) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 46158673 + ... + 46173503.

It is an arithmetic number, because the mean of its divisors is an integer number (26904506400).

Almost surely, 2^684689251128 is an apocalyptic number.

It is an amenable number.

684689251128 is an abundant number, since it is smaller than the sum of its proper divisors (1037199158472).

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

684689251128 is a wasteful number, since it uses less digits than its factorization.

684689251128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26132 (or 26128 counting only the distinct ones).

The product of its digits is 13271040, while the sum is 60.

The spelling of 684689251128 in words is "six hundred eighty-four billion, six hundred eighty-nine million, two hundred fifty-one thousand, one hundred twenty-eight".