1680978420 has 120 divisors (see below), whose sum is σ = 5752742688. Its totient is φ = 407505600.

The previous prime is 1680978401. The next prime is 1680978421. The reversal of 1680978420 is 248790861.

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

It is a zygodrome in base 3.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1680978421) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 29346 + ... + 64985.

Almost surely, 2^1680978420 is an apocalyptic number.

1680978420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1680978420 is an abundant number, since it is smaller than the sum of its proper divisors (4071764268).

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

1680978420 is a wasteful number, since it uses less digits than its factorization.

1680978420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94363 (or 94352 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 45.

The square root of 1680978420 is about 40999.7368284237. The cubic root of 1680978420 is about 1189.0151256115.

It can be divided in two parts, 1680 and 978420, that added together give a square (980100 = 990²).

The spelling of 1680978420 in words is "one billion, six hundred eighty million, nine hundred seventy-eight thousand, four hundred twenty".