20799780 has 48 divisors (see below), whose sum is σ = 59204544. Its totient is φ = 5454720.

The previous prime is 20799769. The next prime is 20799799. The reversal of 20799780 is 8799702.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 819 + ... + 6501.

It is an arithmetic number, because the mean of its divisors is an integer number (1233428).

Almost surely, 2^20799780 is an apocalyptic number.

20799780 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 20799780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29602272).

20799780 is an abundant number, since it is smaller than the sum of its proper divisors (38404764).

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

20799780 is a wasteful number, since it uses less digits than its factorization.

20799780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5756 (or 5754 counting only the distinct ones).

The product of its (nonzero) digits is 63504, while the sum is 42.

The square root of 20799780 is about 4560.6775812372. The cubic root of 20799780 is about 275.0128038116.

The spelling of 20799780 in words is "twenty million, seven hundred ninety-nine thousand, seven hundred eighty".