21471255 has 72 divisors (see below), whose sum is σ = 42911232. Its totient is φ = 9870336.

The previous prime is 21471239. The next prime is 21471257. The reversal of 21471255 is 55217412.

It is not a de Polignac number, because 21471255 - 2⁴ = 21471239 is a prime.

It is a super-2 number, since 2×21471255² = 922029582550050, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21471257) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 169002 + ... + 169128.

Almost surely, 2^21471255 is an apocalyptic number.

21471255 is a deficient number, since it is larger than the sum of its proper divisors (21439977).

21471255 is a wasteful number, since it uses less digits than its factorization.

21471255 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 185 (or 165 counting only the distinct ones).

The product of its digits is 2800, while the sum is 27.

The square root of 21471255 is about 4633.7085579479. The cubic root of 21471255 is about 277.9409109617.

Adding to 21471255 its reverse (55217412), we get a palindrome (76688667).

The spelling of 21471255 in words is "twenty-one million, four hundred seventy-one thousand, two hundred fifty-five".