21213426636511 has 4 divisors (see below), whose sum is σ = 21730827286224. Its totient is φ = 20696025986800.

The previous prime is 21213426636503. The next prime is 21213426636551. The reversal of 21213426636511 is 11563662431212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21213426636511 - 2³ = 21213426636503 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21213426636551) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 258700324795 + ... + 258700324876.

It is an arithmetic number, because the mean of its divisors is an integer number (5432706821556).

Almost surely, 2^{21213426636511} is an apocalyptic number.

21213426636511 is a deficient number, since it is larger than the sum of its proper divisors (517400649713).

21213426636511 is an equidigital number, since it uses as much as digits as its factorization.

21213426636511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 517400649712.

The product of its digits is 311040, while the sum is 43.

The spelling of 21213426636511 in words is "twenty-one trillion, two hundred thirteen billion, four hundred twenty-six million, six hundred thirty-six thousand, five hundred eleven".