21081704103936 has 1026 divisors, whose sum is σ = 75377677318008. Its totient is φ = 5660045475840.

The previous prime is 21081704103907. The next prime is 21081704103979. The reversal of 21081704103936 is 63930140718012.

21081704103936 is a `hidden beast` number, since 2 + 1 + 0 + 8 + 170 + 410 + 39 + 36 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 21081704103891 and 21081704103900.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 33409990341 + ... + 33409990971.

Almost surely, 2^{21081704103936} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21081704103936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37688838659004).

21081704103936 is an abundant number, since it is smaller than the sum of its proper divisors (54295973214072).

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

21081704103936 is an frugal number, since it uses more digits than its factorization.

21081704103936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 721 (or 660 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The spelling of 21081704103936 in words is "twenty-one trillion, eighty-one billion, seven hundred four million, one hundred three thousand, nine hundred thirty-six".