21023921484225 has 405 divisors, whose sum is σ = 43822674447321. Its totient is φ = 9956820931200.

The previous prime is 21023921484173. The next prime is 21023921484263. The reversal of 21023921484225 is 52248412932012.

The square root of 21023921484225 is 4585185.

It is a perfect power (a square), and thus also a powerful number.

21023921484225 is a `hidden beast` number, since 2 + 1 + 0 + 2 + 3 + 9 + 214 + 8 + 422 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 2542726835649 + 18481194648576 = 1594593^2 + 4298976^2 .

It is a tau number, because it is divible by the number of its divisors (405).

It is not a de Polignac number, because 21023921484225 - 2⁹ = 21023921483713 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 404 ways as a sum of consecutive naturals, for example, 133910327847 + ... + 133910328003.

Almost surely, 2^{21023921484225} is an apocalyptic number.

21023921484225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21023921484225 is the 4585185-th square number.

21023921484225 is the 2292593-rd centered octagonal number.

It is an amenable number.

21023921484225 is an abundant number, since it is smaller than the sum of its proper divisors (22798752963096).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21023921484225 is an equidigital number, since it uses as much as digits as its factorization.

21023921484225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 476 (or 235 counting only the distinct ones).

The product of its (nonzero) digits is 552960, while the sum is 45.

The spelling of 21023921484225 in words is "twenty-one trillion, twenty-three billion, nine hundred twenty-one million, four hundred eighty-four thousand, two hundred twenty-five".