21605357233075 has 24 divisors (see below), whose sum is σ = 33401321107200. Its totient is φ = 13468274637600.

The previous prime is 21605357233037. The next prime is 21605357233087. The reversal of 21605357233075 is 57033275350612.

It is a de Polignac number, because none of the positive numbers 2^k-21605357233075 is a prime.

It is a super-2 number, since 2×21605357233075² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5611779175 + ... + 5611783024.

It is an arithmetic number, because the mean of its divisors is an integer number (1391721712800).

Almost surely, 2^{21605357233075} is an apocalyptic number.

21605357233075 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21605357233075 is a deficient number, since it is larger than the sum of its proper divisors (11795963874125).

21605357233075 is a wasteful number, since it uses less digits than its factorization.

21605357233075 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11223562227 (or 11223562222 counting only the distinct ones).

The product of its (nonzero) digits is 3969000, while the sum is 49.

The spelling of 21605357233075 in words is "twenty-one trillion, six hundred five billion, three hundred fifty-seven million, two hundred thirty-three thousand, seventy-five".