20730820 has 96 divisors (see below), whose sum is σ = 52690176. Its totient is φ = 6758400.

The previous prime is 20730799. The next prime is 20730823. The reversal of 20730820 is 2803702.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a junction number, because it is equal to n+sod(n) for n = 20730791 and 20730800.

It is not an unprimeable number, because it can be changed into a prime (20730823) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 85900 + ... + 86140.

It is an arithmetic number, because the mean of its divisors is an integer number (548856).

Almost surely, 2^20730820 is an apocalyptic number.

20730820 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 20730820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26345088).

20730820 is an abundant number, since it is smaller than the sum of its proper divisors (31959356).

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

20730820 is a wasteful number, since it uses less digits than its factorization.

20730820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 301 (or 299 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 22.

The square root of 20730820 is about 4553.1110243437. Note that the first 3 decimals coincide. The cubic root of 20730820 is about 274.7085396881.

The spelling of 20730820 in words is "twenty million, seven hundred thirty thousand, eight hundred twenty".