21255367 has 16 divisors (see below), whose sum is σ = 25600000. Its totient is φ = 17622360.

The previous prime is 21255361. The next prime is 21255383. The reversal of 21255367 is 76355212.

It is not a de Polignac number, because 21255367 - 2⁷ = 21255239 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21255361) 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 15 ways as a sum of consecutive naturals, for example, 9634 + ... + 11632.

It is an arithmetic number, because the mean of its divisors is an integer number (1600000).

Almost surely, 2^21255367 is an apocalyptic number.

21255367 is a deficient number, since it is larger than the sum of its proper divisors (4344633).

21255367 is an equidigital number, since it uses as much as digits as its factorization.

21255367 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2051 (or 2037 counting only the distinct ones).

The product of its digits is 12600, while the sum is 31.

The square root of 21255367 is about 4610.3543247781. The cubic root of 21255367 is about 277.0062295775.

The spelling of 21255367 in words is "twenty-one million, two hundred fifty-five thousand, three hundred sixty-seven".