21213405331265 has 32 divisors (see below), whose sum is σ = 30624851312640. Its totient is φ = 13780293912000.

The previous prime is 21213405331231. The next prime is 21213405331333. The reversal of 21213405331265 is 56213350431212.

It is not a de Polignac number, because 21213405331265 - 2³⁰ = 21212331589441 is a prime.

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, 20775440 + ... + 21772590.

It is an arithmetic number, because the mean of its divisors is an integer number (957026603520).

Almost surely, 2^{21213405331265} is an apocalyptic number.

It is an amenable number.

21213405331265 is a deficient number, since it is larger than the sum of its proper divisors (9411445981375).

21213405331265 is a wasteful number, since it uses less digits than its factorization.

21213405331265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1029173.

The product of its (nonzero) digits is 129600, while the sum is 38.

Adding to 21213405331265 its reverse (56213350431212), we get a palindrome (77426755762477).

The spelling of 21213405331265 in words is "twenty-one trillion, two hundred thirteen billion, four hundred five million, three hundred thirty-one thousand, two hundred sixty-five".