684449136 has 160 divisors (see below), whose sum is σ = 2266283520. Its totient is φ = 193729536.

The previous prime is 684449131. The next prime is 684449137. The reversal of 684449136 is 631944486.

It is a super-2 number, since 2×684449136² = 936941239542292992, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 684449091 and 684449100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (684449131) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 340711 + ... + 342713.

It is an arithmetic number, because the mean of its divisors is an integer number (14164272).

Almost surely, 2^684449136 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 684449136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1133141760).

684449136 is an abundant number, since it is smaller than the sum of its proper divisors (1581834384).

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

684449136 is a wasteful number, since it uses less digits than its factorization.

684449136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2140 (or 2128 counting only the distinct ones).

The product of its digits is 497664, while the sum is 45.

The square root of 684449136 is about 26161.9788242403. The cubic root of 684449136 is about 881.2796191041.

The spelling of 684449136 in words is "six hundred eighty-four million, four hundred forty-nine thousand, one hundred thirty-six".