21366535555602 has 128 divisors (see below), whose sum is σ = 48861210182400. Its totient is φ = 6918506265600.

The previous prime is 21366535555553. The next prime is 21366535555633. The reversal of 21366535555602 is 20655553566312.

21366535555602 is a `hidden beast` number, since 2 + 1 + 3 + 6 + 6 + 535 + 55 + 56 + 0 + 2 = 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 pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 110130202 + ... + 110324042.

It is an arithmetic number, because the mean of its divisors is an integer number (381728204550).

Almost surely, 2^{21366535555602} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21366535555602, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24430605091200).

21366535555602 is an abundant number, since it is smaller than the sum of its proper divisors (27494674626798).

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

21366535555602 is a wasteful number, since it uses less digits than its factorization.

21366535555602 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 194329 (or 194323 counting only the distinct ones).

The product of its (nonzero) digits is 24300000, while the sum is 54.

The spelling of 21366535555602 in words is "twenty-one trillion, three hundred sixty-six billion, five hundred thirty-five million, five hundred fifty-five thousand, six hundred two".