21201926220 has 144 divisors (see below), whose sum is σ = 65617799520. Its totient is φ = 5539995648.

The previous prime is 21201926203. The next prime is 21201926233. The reversal of 21201926220 is 2262910212.

It is a happy number.

21201926220 is a `hidden beast` number, since 2 + 1 + 20 + 19 + 2 + 622 + 0 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2323026 + ... + 2332134.

Almost surely, 2^21201926220 is an apocalyptic number.

21201926220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21201926220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32808899760).

21201926220 is an abundant number, since it is smaller than the sum of its proper divisors (44415873300).

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

21201926220 is a wasteful number, since it uses less digits than its factorization.

21201926220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9384 (or 9379 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The spelling of 21201926220 in words is "twenty-one billion, two hundred one million, nine hundred twenty-six thousand, two hundred twenty".