20357820 has 144 divisors (see below), whose sum is σ = 71705088. Its totient is φ = 4579200.

The previous prime is 20357819. The next prime is 20357837. The reversal of 20357820 is 2875302.

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 47 ways as a sum of consecutive naturals, for example, 134745 + ... + 134895.

It is an arithmetic number, because the mean of its divisors is an integer number (497952).

Almost surely, 2^20357820 is an apocalyptic number.

20357820 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 20357820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35852544).

20357820 is an abundant number, since it is smaller than the sum of its proper divisors (51347268).

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

20357820 is a wasteful number, since it uses less digits than its factorization.

20357820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280 (or 275 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 27.

The square root of 20357820 is about 4511.9640956018. The cubic root of 20357820 is about 273.0509907572.

The spelling of 20357820 in words is "twenty million, three hundred fifty-seven thousand, eight hundred twenty".