21253235366560 has 96 divisors (see below), whose sum is σ = 53179432180560. Its totient is φ = 7998947131392.

The previous prime is 21253235366533. The next prime is 21253235366563. The reversal of 21253235366560 is 6566353235212.

It can be written as a sum of positive squares in 8 ways, for example, as 13945534234384 + 7307701132176 = 3734372^2 + 2703276^2 .

It is not an unprimeable number, because it can be changed into a prime (21253235366563) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8491812 + ... + 10705948.

Almost surely, 2^{21253235366560} is an apocalyptic number.

21253235366560 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21253235366560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26589716090280).

21253235366560 is an abundant number, since it is smaller than the sum of its proper divisors (31926196814000).

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

21253235366560 is a wasteful number, since it uses less digits than its factorization.

21253235366560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2217698 (or 2217690 counting only the distinct ones).

The product of its (nonzero) digits is 5832000, while the sum is 49.

The spelling of 21253235366560 in words is "twenty-one trillion, two hundred fifty-three billion, two hundred thirty-five million, three hundred sixty-six thousand, five hundred sixty".