21371255 has 16 divisors (see below), whose sum is σ = 27095040. Its totient is φ = 16149408.

The previous prime is 21371239. The next prime is 21371263. The reversal of 21371255 is 55217312.

It is a cyclic number.

It is not a de Polignac number, because 21371255 - 2⁴ = 21371239 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8426 + ... + 10664.

It is an arithmetic number, because the mean of its divisors is an integer number (1693440).

Almost surely, 2^21371255 is an apocalyptic number.

21371255 is a deficient number, since it is larger than the sum of its proper divisors (5723785).

21371255 is a wasteful number, since it uses less digits than its factorization.

21371255 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2350.

The product of its digits is 2100, while the sum is 26.

The square root of 21371255 is about 4622.9054716704. The cubic root of 21371255 is about 277.5087463088.

Adding to 21371255 its reverse (55217312), we get a palindrome (76588567).

The spelling of 21371255 in words is "twenty-one million, three hundred seventy-one thousand, two hundred fifty-five".