21404015300221 has 4 divisors (see below), whose sum is σ = 21516078207744. Its totient is φ = 21291952392700.

The previous prime is 21404015300191. The next prime is 21404015300233. The reversal of 21404015300221 is 12200351040412.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21404015300221 - 2²³ = 21404006911613 is a prime.

It is a super-3 number, since 3×21404015300221³ (a number of 41 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21404015300281) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 56031453475 + ... + 56031453856.

It is an arithmetic number, because the mean of its divisors is an integer number (5379019551936).

Almost surely, 2^{21404015300221} is an apocalyptic number.

It is an amenable number.

21404015300221 is a deficient number, since it is larger than the sum of its proper divisors (112062907523).

21404015300221 is a wasteful number, since it uses less digits than its factorization.

21404015300221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112062907522.

The product of its (nonzero) digits is 1920, while the sum is 25.

Adding to 21404015300221 its reverse (12200351040412), we get a palindrome (33604366340633).

The spelling of 21404015300221 in words is "twenty-one trillion, four hundred four billion, fifteen million, three hundred thousand, two hundred twenty-one".