21356211550605 has 32 divisors (see below), whose sum is σ = 34216137384960. Its totient is φ = 11374589721600.

The previous prime is 21356211550561. The next prime is 21356211550631. The reversal of 21356211550605 is 50605511265312.

It is a happy number.

It is not a de Polignac number, because 21356211550605 - 2¹⁷ = 21356211419533 is a prime.

It is a congruent number.

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 31 ways as a sum of consecutive naturals, for example, 34516356 + ... + 35129634.

It is an arithmetic number, because the mean of its divisors is an integer number (1069254293280).

Almost surely, 2^{21356211550605} is an apocalyptic number.

It is an amenable number.

21356211550605 is a deficient number, since it is larger than the sum of its proper divisors (12859925834355).

21356211550605 is a wasteful number, since it uses less digits than its factorization.

21356211550605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 616421.

The product of its (nonzero) digits is 270000, while the sum is 42.

The spelling of 21356211550605 in words is "twenty-one trillion, three hundred fifty-six billion, two hundred eleven million, five hundred fifty thousand, six hundred five".