20820859388 has 24 divisors (see below), whose sum is σ = 43452229632. Its totient is φ = 8535258864.

The previous prime is 20820859387. The next prime is 20820859391. The reversal of 20820859388 is 88395802802.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20820859387) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16164620 + ... + 16165907.

It is an arithmetic number, because the mean of its divisors is an integer number (1810509568).

Almost surely, 2^20820859388 is an apocalyptic number.

20820859388 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

20820859388 is an abundant number, since it is smaller than the sum of its proper divisors (22631370244).

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

20820859388 is a wasteful number, since it uses less digits than its factorization.

20820859388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32330561 (or 32330559 counting only the distinct ones).

The product of its (nonzero) digits is 2211840, while the sum is 53.

The spelling of 20820859388 in words is "twenty billion, eight hundred twenty million, eight hundred fifty-nine thousand, three hundred eighty-eight".