20781300 has 72 divisors (see below), whose sum is σ = 61308576. Its totient is φ = 5432960.

The previous prime is 20781287. The next prime is 20781311. The reversal of 20781300 is 318702.

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 23 ways as a sum of consecutive naturals, for example, 15247 + ... + 16553.

It is an arithmetic number, because the mean of its divisors is an integer number (851508).

Almost surely, 2^20781300 is an apocalyptic number.

20781300 is a gapful number since it is divisible by the number (20) 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 20781300, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30654288).

20781300 is an abundant number, since it is smaller than the sum of its proper divisors (40527276).

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

20781300 is a wasteful number, since it uses less digits than its factorization.

20781300 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1377 (or 1370 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 21.

The square root of 20781300 is about 4558.6511162843. The cubic root of 20781300 is about 274.9313327175.

The spelling of 20781300 in words is "twenty million, seven hundred eighty-one thousand, three hundred".