21535525224320 has 128 divisors (see below), whose sum is σ = 54131748962400. Its totient is φ = 8180820910080.

The previous prime is 21535525224319. The next prime is 21535525224337. The reversal of 21535525224320 is 2342252553512.

It is a tau number, because it is divible by the number of its divisors (128).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8378654 + ... + 10642973.

Almost surely, 2^{21535525224320} is an apocalyptic number.

21535525224320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21535525224320 is an abundant number, since it is smaller than the sum of its proper divisors (32596223738080).

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

21535525224320 is a wasteful number, since it uses less digits than its factorization.

21535525224320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19021736 (or 19021724 counting only the distinct ones).

The product of its (nonzero) digits is 720000, while the sum is 41.

Adding to 21535525224320 its reverse (2342252553512), we get a palindrome (23877777777832).

The spelling of 21535525224320 in words is "twenty-one trillion, five hundred thirty-five billion, five hundred twenty-five million, two hundred twenty-four thousand, three hundred twenty".