685648440 has 192 divisors, whose sum is σ = 2386800000. Its totient is φ = 170180352.

The previous prime is 685648433. The next prime is 685648463. The reversal of 685648440 is 44846586.

685648440 is a `hidden beast` number, since 6 + 8 + 564 + 84 + 4 + 0 = 666.

It is a super-2 number, since 2×685648440² = 940227566548867200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 402711 + ... + 404409.

It is an arithmetic number, because the mean of its divisors is an integer number (12431250).

Almost surely, 2^685648440 is an apocalyptic number.

685648440 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 685648440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1193400000).

685648440 is an abundant number, since it is smaller than the sum of its proper divisors (1701151560).

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

685648440 is a wasteful number, since it uses less digits than its factorization.

685648440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1794 (or 1787 counting only the distinct ones).

The product of its (nonzero) digits is 737280, while the sum is 45.

The square root of 685648440 is about 26184.8895357609. The cubic root of 685648440 is about 881.7940500519.

The spelling of 685648440 in words is "six hundred eighty-five million, six hundred forty-eight thousand, four hundred forty".