20105904899838 has 48 divisors (see below), whose sum is σ = 41133021340464. Its totient is φ = 6550109130240.

The previous prime is 20105904899833. The next prime is 20105904899881. The reversal of 20105904899838 is 83899840950102.

It is a happy number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20105904899833) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7907206 + ... + 10135862.

It is an arithmetic number, because the mean of its divisors is an integer number (856937944593).

Almost surely, 2^{20105904899838} is an apocalyptic number.

20105904899838 is an abundant number, since it is smaller than the sum of its proper divisors (21027116440626).

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

20105904899838 is a wasteful number, since it uses less digits than its factorization.

20105904899838 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2229037 (or 2228880 counting only the distinct ones).

The product of its (nonzero) digits is 44789760, while the sum is 66.

The spelling of 20105904899838 in words is "twenty trillion, one hundred five billion, nine hundred four million, eight hundred ninety-nine thousand, eight hundred thirty-eight".