21021223434225 has 48 divisors (see below), whose sum is σ = 39737749954560. Its totient is φ = 9605432520000.

The previous prime is 21021223434203. The next prime is 21021223434227. The reversal of 21021223434225 is 52243432212012.

It is not a de Polignac number, because 21021223434225 - 2⁶ = 21021223434161 is a prime.

It is a super-2 number, since 2×21021223434225² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21021223434227) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7712145 + ... + 10075694.

It is an arithmetic number, because the mean of its divisors is an integer number (827869790720).

Almost surely, 2^{21021223434225} is an apocalyptic number.

21021223434225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21021223434225 is a deficient number, since it is larger than the sum of its proper divisors (18716526520335).

21021223434225 is a wasteful number, since it uses less digits than its factorization.

21021223434225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17790110 (or 17790105 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 33.

Adding to 21021223434225 its reverse (52243432212012), we get a palindrome (73264655646237).

The spelling of 21021223434225 in words is "twenty-one trillion, twenty-one billion, two hundred twenty-three million, four hundred thirty-four thousand, two hundred twenty-five".