21801255 has 32 divisors (see below), whose sum is σ = 40041984. Its totient is φ = 9922176.

The previous prime is 21801211. The next prime is 21801271. The reversal of 21801255 is 55210812.

It is not a de Polignac number, because 21801255 - 2¹² = 21797159 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 41424 + ... + 41946.

It is an arithmetic number, because the mean of its divisors is an integer number (1251312).

Almost surely, 2^21801255 is an apocalyptic number.

21801255 is a deficient number, since it is larger than the sum of its proper divisors (18240729).

21801255 is a wasteful number, since it uses less digits than its factorization.

21801255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 935.

The product of its (nonzero) digits is 800, while the sum is 24.

The square root of 21801255 is about 4669.1814057713. The cubic root of 21801255 is about 279.3576046804.

The spelling of 21801255 in words is "twenty-one million, eight hundred one thousand, two hundred fifty-five".