21253212051245 has 8 divisors (see below), whose sum is σ = 25504001948184. Its totient is φ = 17002471316544.

The previous prime is 21253212051193. The next prime is 21253212051283. The reversal of 21253212051245 is 54215021235212.

It can be written as a sum of positive squares in 4 ways, for example, as 1287230884 + 21251924820361 = 35878^2 + 4609981^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21253212051245 - 2⁴² = 16855165540141 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11332694 + ... + 13074263.

It is an arithmetic number, because the mean of its divisors is an integer number (3188000243523).

Almost surely, 2^{21253212051245} is an apocalyptic number.

It is an amenable number.

21253212051245 is a deficient number, since it is larger than the sum of its proper divisors (4250789896939).

21253212051245 is a wasteful number, since it uses less digits than its factorization.

21253212051245 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24581119.

The product of its (nonzero) digits is 48000, while the sum is 35.

Adding to 21253212051245 its reverse (54215021235212), we get a palindrome (75468233286457).

The spelling of 21253212051245 in words is "twenty-one trillion, two hundred fifty-three billion, two hundred twelve million, fifty-one thousand, two hundred forty-five".