20878780 has 48 divisors (see below), whose sum is σ = 47656224. Its totient is φ = 7637760.

The previous prime is 20878769. The next prime is 20878787. The reversal of 20878780 is 8787802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20878787) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33754 + ... + 34366.

It is an arithmetic number, because the mean of its divisors is an integer number (992838).

Almost surely, 2^20878780 is an apocalyptic number.

20878780 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 20878780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23828112).

20878780 is an abundant number, since it is smaller than the sum of its proper divisors (26777444).

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

20878780 is a wasteful number, since it uses less digits than its factorization.

20878780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 766 (or 764 counting only the distinct ones).

The product of its (nonzero) digits is 50176, while the sum is 40.

The square root of 20878780 is about 4569.3303666949. The cubic root of 20878780 is about 275.3605408776.

The spelling of 20878780 in words is "twenty million, eight hundred seventy-eight thousand, seven hundred eighty".