21506730621120 has 224 divisors, whose sum is σ = 77921534174400. Its totient is φ = 5580124618752.

The previous prime is 21506730621043. The next prime is 21506730621161. The reversal of 21506730621120 is 2112603760512.

21506730621120 is a `hidden beast` number, since 2 + 1 + 5 + 0 + 6 + 7 + 3 + 0 + 621 + 1 + 20 = 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 31 ways as a sum of consecutive naturals, for example, 33318225 + ... + 33957584.

It is an arithmetic number, because the mean of its divisors is an integer number (347863991850).

Almost surely, 2^{21506730621120} is an apocalyptic number.

21506730621120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21506730621120 is an abundant number, since it is smaller than the sum of its proper divisors (56414803553280).

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

21506730621120 is a wasteful number, since it uses less digits than its factorization.

21506730621120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67275872 (or 67275856 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The spelling of 21506730621120 in words is "twenty-one trillion, five hundred six billion, seven hundred thirty million, six hundred twenty-one thousand, one hundred twenty".