21504525355321 has 8 divisors (see below), whose sum is σ = 21601313936384. Its totient is φ = 21407739950880.

The previous prime is 21504525355319. The next prime is 21504525355337. The reversal of 21504525355321 is 12355352540512.

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 21504525355321 - 2¹ = 21504525355319 is a prime.

It is a super-2 number, since 2×21504525355321² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21504525355301) 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, 13340320 + ... + 14865166.

It is an arithmetic number, because the mean of its divisors is an integer number (2700164242048).

Almost surely, 2^{21504525355321} is an apocalyptic number.

It is an amenable number.

21504525355321 is a deficient number, since it is larger than the sum of its proper divisors (96788581063).

21504525355321 is a wasteful number, since it uses less digits than its factorization.

21504525355321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1588311.

The product of its (nonzero) digits is 900000, while the sum is 43.

Adding to 21504525355321 its reverse (12355352540512), we get a palindrome (33859877895833).

The spelling of 21504525355321 in words is "twenty-one trillion, five hundred four billion, five hundred twenty-five million, three hundred fifty-five thousand, three hundred twenty-one".