21553343434551 has 64 divisors (see below), whose sum is σ = 29522876866560. Its totient is φ = 13982740041600.

The previous prime is 21553343434523. The next prime is 21553343434591. The reversal of 21553343434551 is 15543434335512.

It is a happy number.

It is not a de Polignac number, because 21553343434551 - 2⁹ = 21553343434039 is a prime.

It is a super-2 number, since 2×21553343434551² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21553343434551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21553343434591) 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 63 ways as a sum of consecutive naturals, for example, 11337896701 + ... + 11337898601.

It is an arithmetic number, because the mean of its divisors is an integer number (461294951040).

Almost surely, 2^{21553343434551} is an apocalyptic number.

21553343434551 is a deficient number, since it is larger than the sum of its proper divisors (7969533432009).

21553343434551 is a wasteful number, since it uses less digits than its factorization.

21553343434551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3916.

The product of its digits is 6480000, while the sum is 48.

The spelling of 21553343434551 in words is "twenty-one trillion, five hundred fifty-three billion, three hundred forty-three million, four hundred thirty-four thousand, five hundred fifty-one".