20816138308280 has 64 divisors (see below), whose sum is σ = 53540832314880. Its totient is φ = 7135145769600.

The previous prime is 20816138308253. The next prime is 20816138308349. The reversal of 20816138308280 is 8280383161802.

It is a happy number.

It is a super-2 number, since 2×20816138308280² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8355356 + ... + 10556715.

It is an arithmetic number, because the mean of its divisors is an integer number (836575504920).

Almost surely, 2^{20816138308280} is an apocalyptic number.

20816138308280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20816138308280 is an abundant number, since it is smaller than the sum of its proper divisors (32724694006600).

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

20816138308280 is a wasteful number, since it uses less digits than its factorization.

20816138308280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18916020 (or 18916016 counting only the distinct ones).

The product of its (nonzero) digits is 884736, while the sum is 50.

The spelling of 20816138308280 in words is "twenty trillion, eight hundred sixteen billion, one hundred thirty-eight million, three hundred eight thousand, two hundred eighty".