21243941083225 has 243 divisors, whose sum is σ = 33635384307837. Its totient is φ = 13268941499520.

The previous prime is 21243941083177. The next prime is 21243941083247. The reversal of 21243941083225 is 52238014934212.

The square root of 21243941083225 is 4609115.

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

It can be written as a sum of positive squares in 4 ways, for example, as 292009463641 + 20951931619584 = 540379^2 + 4577328^2 .

It is not a de Polignac number, because 21243941083225 - 2³⁵ = 21209581344857 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 242 ways as a sum of consecutive naturals, for example, 88886782656 + ... + 88886782894.

Almost surely, 2^{21243941083225} is an apocalyptic number.

21243941083225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21243941083225 is the 4609115-th square number.

21243941083225 is the 2304558-th centered octagonal number.

It is an amenable number.

21243941083225 is a deficient number, since it is larger than the sum of its proper divisors (12391443224612).

21243941083225 is an equidigital number, since it uses as much as digits as its factorization.

21243941083225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 598 (or 299 counting only the distinct ones).

The product of its (nonzero) digits is 829440, while the sum is 46.

The spelling of 21243941083225 in words is "twenty-one trillion, two hundred forty-three billion, nine hundred forty-one million, eighty-three thousand, two hundred twenty-five".