21356254302523 has 8 divisors (see below), whose sum is σ = 24407177946080. Its totient is φ = 18305338201920.

The previous prime is 21356254302499. The next prime is 21356254302533. The reversal of 21356254302523 is 32520345265312.

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

It is a de Polignac number, because none of the positive numbers 2^k-21356254302523 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21356254302523.

It is not an unprimeable number, because it can be changed into a prime (21356254302533) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6926983 + ... + 9523423.

It is an arithmetic number, because the mean of its divisors is an integer number (3050897243260).

Almost surely, 2^{21356254302523} is an apocalyptic number.

21356254302523 is a deficient number, since it is larger than the sum of its proper divisors (3050923643557).

21356254302523 is a wasteful number, since it uses less digits than its factorization.

21356254302523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3771477.

The product of its (nonzero) digits is 1296000, while the sum is 43.

Adding to 21356254302523 its reverse (32520345265312), we get a palindrome (53876599567835).

The spelling of 21356254302523 in words is "twenty-one trillion, three hundred fifty-six billion, two hundred fifty-four million, three hundred two thousand, five hundred twenty-three".