20421902654208 has 864 divisors, whose sum is σ = 70227872612352. Its totient is φ = 5637006950400.

The previous prime is 20421902654141. The next prime is 20421902654213. The reversal of 20421902654208 is 80245620912402.

20421902654208 is a `hidden beast` number, since 2 + 0 + 4 + 219 + 0 + 2 + 6 + 5 + 420 + 8 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2243420985 + ... + 2243430087.

It is an arithmetic number, because the mean of its divisors is an integer number (81282259968).

Almost surely, 2^{20421902654208} 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 20421902654208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35113936306176).

20421902654208 is an abundant number, since it is smaller than the sum of its proper divisors (49805969958144).

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

20421902654208 is a wasteful number, since it uses less digits than its factorization.

20421902654208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9321 (or 9304 counting only the distinct ones).

The product of its (nonzero) digits is 552960, while the sum is 45.

The spelling of 20421902654208 in words is "twenty trillion, four hundred twenty-one billion, nine hundred two million, six hundred fifty-four thousand, two hundred eight".