21455333213421 has 8 divisors (see below), whose sum is σ = 29380276112224. Its totient is φ = 13916972895120.

The previous prime is 21455333213407. The next prime is 21455333213429. The reversal of 21455333213421 is 12431233355412.

It is a happy number.

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

It is not a de Polignac number, because 21455333213421 - 2³⁰ = 21454259471597 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21455333213421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21455333213429) 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, 96645644995 + ... + 96645645216.

It is an arithmetic number, because the mean of its divisors is an integer number (3672534514028).

Almost surely, 2^{21455333213421} is an apocalyptic number.

It is an amenable number.

21455333213421 is a deficient number, since it is larger than the sum of its proper divisors (7924942898803).

21455333213421 is a wasteful number, since it uses less digits than its factorization.

21455333213421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 193291290251.

The product of its digits is 259200, while the sum is 39.

Adding to 21455333213421 its reverse (12431233355412), we get a palindrome (33886566568833).

The spelling of 21455333213421 in words is "twenty-one trillion, four hundred fifty-five billion, three hundred thirty-three million, two hundred thirteen thousand, four hundred twenty-one".