21120500520 has 224 divisors, whose sum is σ = 81428325120. Its totient is φ = 4827496320.

The previous prime is 21120500503. The next prime is 21120500573. The reversal of 21120500520 is 2500502112.

21120500520 is a `hidden beast` number, since 2 + 112 + 0 + 500 + 52 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21120500493 and 21120500502.

It is an unprimeable number.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 152385 + ... + 255855.

Almost surely, 2^21120500520 is an apocalyptic number.

21120500520 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 21120500520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40714162560).

21120500520 is an abundant number, since it is smaller than the sum of its proper divisors (60307824600).

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

21120500520 is a wasteful number, since it uses less digits than its factorization.

21120500520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103507 (or 103488 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 18.

The spelling of 21120500520 in words is "twenty-one billion, one hundred twenty million, five hundred thousand, five hundred twenty".