21000255904338 has 16 divisors (see below), whose sum is σ = 43448805319680. Its totient is φ = 6758703049616.

The previous prime is 21000255904319. The next prime is 21000255904339. The reversal of 21000255904338 is 83340955200012.

It is a self number, because there is not a number n which added to its sum of digits gives 21000255904338.

It is not an unprimeable number, because it can be changed into a prime (21000255904339) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 60345562770 + ... + 60345563117.

It is an arithmetic number, because the mean of its divisors is an integer number (2715550332480).

Almost surely, 2^{21000255904338} is an apocalyptic number.

21000255904338 is an abundant number, since it is smaller than the sum of its proper divisors (22448549415342).

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

21000255904338 is a wasteful number, since it uses less digits than its factorization.

21000255904338 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120691125921.

The product of its (nonzero) digits is 259200, while the sum is 42.

The spelling of 21000255904338 in words is "twenty-one trillion, two hundred fifty-five million, nine hundred four thousand, three hundred thirty-eight".