21621555034205 has 8 divisors (see below), whose sum is σ = 29652418332672. Its totient is φ = 14826209166288.

The previous prime is 21621555034103. The next prime is 21621555034207. The reversal of 21621555034205 is 50243055512612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21621555034205 - 2²⁶ = 21621487925341 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 (21621555034207) 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 7 ways as a sum of consecutive naturals, for example, 308879357597 + ... + 308879357666.

It is an arithmetic number, because the mean of its divisors is an integer number (3706552291584).

Almost surely, 2^{21621555034205} is an apocalyptic number.

It is an amenable number.

21621555034205 is a deficient number, since it is larger than the sum of its proper divisors (8030863298467).

21621555034205 is an equidigital number, since it uses as much as digits as its factorization.

21621555034205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 617758715275.

The product of its (nonzero) digits is 360000, while the sum is 41.

The spelling of 21621555034205 in words is "twenty-one trillion, six hundred twenty-one billion, five hundred fifty-five million, thirty-four thousand, two hundred five".