1680445440 has 260 divisors, whose sum is σ = 6029919324. Its totient is φ = 447676416.

The previous prime is 1680445433. The next prime is 1680445441. The reversal of 1680445440 is 445440861.

It is a happy number.

1680445440 is a `hidden beast` number, since 168 + 0 + 4 + 454 + 40 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 191102976 + 1489342464 = 13824^2 + 38592^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 1680445395 and 1680445404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1680445441) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1658374 + ... + 1659386.

Almost surely, 2^1680445440 is an apocalyptic number.

1680445440 is a gapful number since it is divisible by the number (10) 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 1680445440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3014959662).

1680445440 is an abundant number, since it is smaller than the sum of its proper divisors (4349473884).

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

1680445440 is an equidigital number, since it uses as much as digits as its factorization.

1680445440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1054 (or 1023 counting only the distinct ones).

The product of its (nonzero) digits is 61440, while the sum is 36.

The square root of 1680445440 is about 40993.2365153082. The cubic root of 1680445440 is about 1188.8894471648.

The spelling of 1680445440 in words is "one billion, six hundred eighty million, four hundred forty-five thousand, four hundred forty".