684239400 has 504 divisors, whose sum is σ = 2710978830. Its totient is φ = 159563520.

The previous prime is 684239359. The next prime is 684239401. The reversal of 684239400 is 4932486.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 380016036 + 304223364 = 19494^2 + 17442^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (684239401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 125 ways as a sum of consecutive naturals, for example, 36012591 + ... + 36012609.

Almost surely, 2^684239400 is an apocalyptic number.

684239400 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 684239400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1355489415).

684239400 is an abundant number, since it is smaller than the sum of its proper divisors (2026739430).

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

684239400 is a wasteful number, since it uses less digits than its factorization.

684239400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85 (or 42 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The square root of 684239400 is about 26157.9701047310. The cubic root of 684239400 is about 881.1895929621.

The spelling of 684239400 in words is "six hundred eighty-four million, two hundred thirty-nine thousand, four hundred".