20817994338 has 24 divisors (see below), whose sum is σ = 45956706588. Its totient is φ = 6808400352.

The previous prime is 20817994291. The next prime is 20817994339. The reversal of 20817994338 is 83349971802.

20817994338 is a `hidden beast` number, since 208 + 17 + 9 + 94 + 338 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 19981801449 + 836192889 = 141357^2 + 28917^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20817994339) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10909945 + ... + 10911852.

Almost surely, 2^20817994338 is an apocalyptic number.

20817994338 is an abundant number, since it is smaller than the sum of its proper divisors (25138712250).

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

20817994338 is a wasteful number, since it uses less digits than its factorization.

20817994338 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21821858 (or 21821855 counting only the distinct ones).

The product of its (nonzero) digits is 2612736, while the sum is 54.

The spelling of 20817994338 in words is "twenty billion, eight hundred seventeen million, nine hundred ninety-four thousand, three hundred thirty-eight".