21120213155535 has 48 divisors (see below), whose sum is σ = 40385968616448. Its totient is φ = 10144042329600.

The previous prime is 21120213155519. The next prime is 21120213155549. The reversal of 21120213155535 is 53555131202112.

21120213155535 is a `hidden beast` number, since 2 + 1 + 1 + 20 + 21 + 31 + 55 + 535 = 666.

It is not a de Polignac number, because 21120213155535 - 2⁴ = 21120213155519 is a prime.

It is a super-2 number, since 2×21120213155535² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21120213155535.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 440255631 + ... + 440303600.

It is an arithmetic number, because the mean of its divisors is an integer number (841374346176).

Almost surely, 2^{21120213155535} is an apocalyptic number.

21120213155535 is a deficient number, since it is larger than the sum of its proper divisors (19265755460913).

21120213155535 is a wasteful number, since it uses less digits than its factorization.

21120213155535 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 880559296 (or 880559293 counting only the distinct ones).

The product of its (nonzero) digits is 45000, while the sum is 36.

Adding to 21120213155535 its reverse (53555131202112), we get a palindrome (74675344357647).

The spelling of 21120213155535 in words is "twenty-one trillion, one hundred twenty billion, two hundred thirteen million, one hundred fifty-five thousand, five hundred thirty-five".