21024412404421 has 2 divisors, whose sum is σ = 21024412404422. Its totient is φ = 21024412404420.

The previous prime is 21024412404403. The next prime is 21024412404601. The reversal of 21024412404421 is 12440421442012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20938586256900 + 85826147521 = 4575870^2 + 292961^2 .

It is a cyclic number.

It is not a de Polignac number, because 21024412404421 - 2²⁷ = 21024278186693 is a prime.

It is a super-2 number, since 2×21024412404421² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21024412408421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10512206202210 + 10512206202211.

It is an arithmetic number, because the mean of its divisors is an integer number (10512206202211).

Almost surely, 2^{21024412404421} is an apocalyptic number.

It is an amenable number.

21024412404421 is a deficient number, since it is larger than the sum of its proper divisors (1).

21024412404421 is an equidigital number, since it uses as much as digits as its factorization.

21024412404421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16384, while the sum is 31.

Adding to 21024412404421 its reverse (12440421442012), we get a palindrome (33464833846433).

The spelling of 21024412404421 in words is "twenty-one trillion, twenty-four billion, four hundred twelve million, four hundred four thousand, four hundred twenty-one".