20685323990016 has 396 divisors, whose sum is σ = 69535542189828. Its totient is φ = 5905368612864.

The previous prime is 20685323989991. The next prime is 20685323990041. The reversal of 20685323990016 is 61009932358602.

20685323990016 is a `hidden beast` number, since 2 + 0 + 6 + 8 + 532 + 3 + 9 + 90 + 0 + 16 = 666.

It is an interprime number because it is at equal distance from previous prime (20685323989991) and next prime (20685323990041).

It can be written as a sum of positive squares in 2 ways, for example, as 17319713596416 + 3365610393600 = 4161696^2 + 1834560^2 .

It is a congruent number.

It is an unprimeable number.

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 35 ways as a sum of consecutive naturals, for example, 585686790 + ... + 585722106.

Almost surely, 2^{20685323990016} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20685323990016, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34767771094914).

20685323990016 is an abundant number, since it is smaller than the sum of its proper divisors (48850218199812).

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

20685323990016 is a wasteful number, since it uses less digits than its factorization.

20685323990016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36654 (or 36626 counting only the distinct ones).

The product of its (nonzero) digits is 4199040, while the sum is 54.

The spelling of 20685323990016 in words is "twenty trillion, six hundred eighty-five billion, three hundred twenty-three million, nine hundred ninety thousand, sixteen".