20909564121920 has 112 divisors (see below), whose sum is σ = 51510002654160. Its totient is φ = 8075076796416.

The previous prime is 20909564121913. The next prime is 20909564121931. The reversal of 20909564121920 is 2912146590902.

It can be written as a sum of positive squares in 8 ways, for example, as 8616854960704 + 12292709161216 = 2935448^2 + 3506096^2 .

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, 410827994 + ... + 410878886.

Almost surely, 2^{20909564121920} is an apocalyptic number.

20909564121920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20909564121920 is an abundant number, since it is smaller than the sum of its proper divisors (30600438532240).

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

20909564121920 is a wasteful number, since it uses less digits than its factorization.

20909564121920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95212 (or 95202 counting only the distinct ones).

The product of its (nonzero) digits is 699840, while the sum is 50.

The spelling of 20909564121920 in words is "twenty trillion, nine hundred nine billion, five hundred sixty-four million, one hundred twenty-one thousand, nine hundred twenty".