21006839904930 has 320 divisors, whose sum is σ = 61841124753408. Its totient is φ = 5074323200640.

The previous prime is 21006839904917. The next prime is 21006839904977. The reversal of 21006839904930 is 3940993860012.

21006839904930 is a `hidden beast` number, since 2 + 1 + 0 + 0 + 68 + 3 + 9 + 90 + 493 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 5437958179 + ... + 5437962041.

Almost surely, 2^{21006839904930} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21006839904930, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30920562376704).

21006839904930 is an abundant number, since it is smaller than the sum of its proper divisors (40834284848478).

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

21006839904930 is a wasteful number, since it uses less digits than its factorization.

21006839904930 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5923 (or 5914 counting only the distinct ones).

The product of its (nonzero) digits is 2519424, while the sum is 54.

The spelling of 21006839904930 in words is "twenty-one trillion, six billion, eight hundred thirty-nine million, nine hundred four thousand, nine hundred thirty".