21005253611260 has 12 divisors (see below), whose sum is σ = 44111032583688. Its totient is φ = 8402101444496.

The previous prime is 21005253611171. The next prime is 21005253611263. The reversal of 21005253611260 is 6211635250012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21005253611263) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 525131340262 + ... + 525131340301.

It is an arithmetic number, because the mean of its divisors is an integer number (3675919381974).

Almost surely, 2^{21005253611260} is an apocalyptic number.

21005253611260 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21005253611260 is an abundant number, since it is smaller than the sum of its proper divisors (23105778972428).

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

21005253611260 is a wasteful number, since it uses less digits than its factorization.

21005253611260 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1050262680572 (or 1050262680570 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 34.

Adding to 21005253611260 its reverse (6211635250012), we get a palindrome (27216888861272).

The spelling of 21005253611260 in words is "twenty-one trillion, five billion, two hundred fifty-three million, six hundred eleven thousand, two hundred sixty".