20681980 has 24 divisors (see below), whose sum is σ = 47381040. Its totient is φ = 7520640.

The previous prime is 20681957. The next prime is 20681993. The reversal of 20681980 is 8918602.

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, 46785 + ... + 47224.

It is an arithmetic number, because the mean of its divisors is an integer number (1974210).

Almost surely, 2^20681980 is an apocalyptic number.

20681980 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20681980 is an abundant number, since it is smaller than the sum of its proper divisors (26699060).

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

20681980 is a wasteful number, since it uses less digits than its factorization.

20681980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94029 (or 94027 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 34.

The square root of 20681980 is about 4547.7444959012. The cubic root of 20681980 is about 274.4926402827.

The spelling of 20681980 in words is "twenty million, six hundred eighty-one thousand, nine hundred eighty".