1681780220 has 24 divisors (see below), whose sum is σ = 3532537008. Its totient is φ = 672560000.

The previous prime is 1681780183. The next prime is 1681780297. The reversal of 1681780220 is 220871861.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 134015 + ... + 146025.

It is an arithmetic number, because the mean of its divisors is an integer number (147189042).

Almost surely, 2^1681780220 is an apocalyptic number.

1681780220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1681780220 is an abundant number, since it is smaller than the sum of its proper divisors (1850756788).

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

1681780220 is a wasteful number, since it uses less digits than its factorization.

1681780220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19021 (or 19019 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 35.

The square root of 1681780220 is about 41009.5137742451. The cubic root of 1681780220 is about 1189.2041426702.

The spelling of 1681780220 in words is "one billion, six hundred eighty-one million, seven hundred eighty thousand, two hundred twenty".