21655225234252 has 12 divisors (see below), whose sum is σ = 39544324340976. Its totient is φ = 10356846851120.

The previous prime is 21655225234213. The next prime is 21655225234273. The reversal of 21655225234252 is 25243252255612.

It is a Harshad number since it is a multiple of its sum of digits (46).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 117691441399 + ... + 117691441582.

It is an arithmetic number, because the mean of its divisors is an integer number (3295360361748).

Almost surely, 2^{21655225234252} is an apocalyptic number.

It is an amenable number.

21655225234252 is a deficient number, since it is larger than the sum of its proper divisors (17889099106724).

21655225234252 is a wasteful number, since it uses less digits than its factorization.

21655225234252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 235382883008 (or 235382883006 counting only the distinct ones).

The product of its digits is 2880000, while the sum is 46.

Adding to 21655225234252 its reverse (25243252255612), we get a palindrome (46898477489864).

The spelling of 21655225234252 in words is "twenty-one trillion, six hundred fifty-five billion, two hundred twenty-five million, two hundred thirty-four thousand, two hundred fifty-two".