21106243620 has 288 divisors, whose sum is σ = 80151192576. Its totient is φ = 4367520000.

The previous prime is 21106243607. The next prime is 21106243649. The reversal of 21106243620 is 2634260112.

21106243620 is a `hidden beast` number, since 2 + 1 + 1 + 0 + 624 + 36 + 2 + 0 = 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, 3475827 + ... + 3481893.

It is an arithmetic number, because the mean of its divisors is an integer number (278302752).

Almost surely, 2^21106243620 is an apocalyptic number.

21106243620 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 21106243620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40075596288).

21106243620 is an abundant number, since it is smaller than the sum of its proper divisors (59044948956).

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

21106243620 is a wasteful number, since it uses less digits than its factorization.

21106243620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6351 (or 6346 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The spelling of 21106243620 in words is "twenty-one billion, one hundred six million, two hundred forty-three thousand, six hundred twenty".