21430423441021 has 6 divisors (see below), whose sum is σ = 24929268084510. Its totient is φ = 18368934377976.

The previous prime is 21430423441001. The next prime is 21430423441061. The reversal of 21430423441021 is 12014432403412.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 14678668125625 + 6751755315396 = 3831275^2 + 2598414^2 .

It is not a de Polignac number, because 21430423441021 - 2²³ = 21430415052413 is a prime.

It is a super-2 number, since 2×21430423441021² (a number of 27 digits) contains 22 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 (21430423441001) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 218677790166 + ... + 218677790263.

It is an arithmetic number, because the mean of its divisors is an integer number (4154878014085).

Almost surely, 2^{21430423441021} is an apocalyptic number.

It is an amenable number.

21430423441021 is a deficient number, since it is larger than the sum of its proper divisors (3498844643489).

21430423441021 is an equidigital number, since it uses as much as digits as its factorization.

21430423441021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 437355580443 (or 437355580436 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 31.

Adding to 21430423441021 its reverse (12014432403412), we get a palindrome (33444855844433).

The spelling of 21430423441021 in words is "twenty-one trillion, four hundred thirty billion, four hundred twenty-three million, four hundred forty-one thousand, twenty-one".