20787900 has 144 divisors (see below), whose sum is σ = 72495360. Its totient is φ = 4492800.

The previous prime is 20787869. The next prime is 20787901. The reversal of 20787900 is 978702.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20787901) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 39640 + ... + 40160.

It is an arithmetic number, because the mean of its divisors is an integer number (503440).

Almost surely, 2^20787900 is an apocalyptic number.

20787900 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 20787900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36247680).

20787900 is an abundant number, since it is smaller than the sum of its proper divisors (51707460).

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

20787900 is a wasteful number, since it uses less digits than its factorization.

20787900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 564 (or 557 counting only the distinct ones).

The product of its (nonzero) digits is 7056, while the sum is 33.

The square root of 20787900 is about 4559.3749571624. The cubic root of 20787900 is about 274.9604350793.

The spelling of 20787900 in words is "twenty million, seven hundred eighty-seven thousand, nine hundred".