21107510243820 has 5760 divisors, whose sum is σ = 101742778368000. Its totient is φ = 3621252096000.

The previous prime is 21107510243791. The next prime is 21107510243881. The reversal of 21107510243820 is 2834201570112.

21107510243820 is a `hidden beast` number, since 2 + 1 + 107 + 510 + 2 + 4 + 38 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 1919 ways as a sum of consecutive naturals, for example, 514817323000 + ... + 514817323040.

It is an arithmetic number, because the mean of its divisors is an integer number (17663676800).

Almost surely, 2^{21107510243820} is an apocalyptic number.

21107510243820 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 21107510243820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50871389184000).

21107510243820 is an abundant number, since it is smaller than the sum of its proper divisors (80635268124180).

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

21107510243820 is a wasteful number, since it uses less digits than its factorization.

21107510243820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168 (or 132 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 36.

The spelling of 21107510243820 in words is "twenty-one trillion, one hundred seven billion, five hundred ten million, two hundred forty-three thousand, eight hundred twenty".