21551432213345 has 16 divisors (see below), whose sum is σ = 26054287383168. Its totient is φ = 17112803306880.

The previous prime is 21551432213329. The next prime is 21551432213429. The reversal of 21551432213345 is 54331223415512.

It is not a de Polignac number, because 21551432213345 - 2⁴ = 21551432213329 is a prime.

It is a Duffinian 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 15 ways as a sum of consecutive naturals, for example, 2417162 + ... + 6996108.

It is an arithmetic number, because the mean of its divisors is an integer number (1628392961448).

Almost surely, 2^{21551432213345} is an apocalyptic number.

It is an amenable number.

21551432213345 is a deficient number, since it is larger than the sum of its proper divisors (4502855169823).

21551432213345 is a wasteful number, since it uses less digits than its factorization.

21551432213345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4585960.

The product of its digits is 432000, while the sum is 41.

Adding to 21551432213345 its reverse (54331223415512), we get a palindrome (75882655628857).

The spelling of 21551432213345 in words is "twenty-one trillion, five hundred fifty-one billion, four hundred thirty-two million, two hundred thirteen thousand, three hundred forty-five".