21215125344255 has 32 divisors (see below), whose sum is σ = 34295147040000. Its totient is φ = 11197758200832.

The previous prime is 21215125344251. The next prime is 21215125344293. The reversal of 21215125344255 is 55244352151212.

It is not a de Polignac number, because 21215125344255 - 2² = 21215125344251 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21215125344251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 54132996 + ... + 54523494.

It is an arithmetic number, because the mean of its divisors is an integer number (1071723345000).

Almost surely, 2^{21215125344255} is an apocalyptic number.

21215125344255 is a deficient number, since it is larger than the sum of its proper divisors (13080021695745).

21215125344255 is a wasteful number, since it uses less digits than its factorization.

21215125344255 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 427943.

The product of its digits is 480000, while the sum is 42.

Adding to 21215125344255 its reverse (55244352151212), we get a palindrome (76459477495467).

The spelling of 21215125344255 in words is "twenty-one trillion, two hundred fifteen billion, one hundred twenty-five million, three hundred forty-four thousand, two hundred fifty-five".