20641880 has 32 divisors (see below), whose sum is σ = 53079840. Its totient is φ = 7077120.

The previous prime is 20641871. The next prime is 20641909. The reversal of 20641880 is 8814602.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36581 + ... + 37140.

It is an arithmetic number, because the mean of its divisors is an integer number (1658745).

Almost surely, 2^20641880 is an apocalyptic number.

20641880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20641880 is an abundant number, since it is smaller than the sum of its proper divisors (32437960).

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

20641880 is a wasteful number, since it uses less digits than its factorization.

20641880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73739 (or 73735 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 29.

The square root of 20641880 is about 4543.3335778919. Note that the first 3 decimals coincide. The cubic root of 20641880 is about 274.3151221982.

The spelling of 20641880 in words is "twenty million, six hundred forty-one thousand, eight hundred eighty".