21255373 has 8 divisors (see below), whose sum is σ = 21877856. Its totient is φ = 20638800.

The previous prime is 21255361. The next prime is 21255383. The reversal of 21255373 is 37355212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21255373 - 2⁹ = 21254861 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21255323) 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 7 ways as a sum of consecutive naturals, for example, 6418 + ... + 9148.

It is an arithmetic number, because the mean of its divisors is an integer number (2734732).

Almost surely, 2^21255373 is an apocalyptic number.

It is an amenable number.

21255373 is a deficient number, since it is larger than the sum of its proper divisors (622483).

21255373 is a wasteful number, since it uses less digits than its factorization.

21255373 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2955.

The product of its digits is 6300, while the sum is 28.

The square root of 21255373 is about 4610.3549754872. The cubic root of 21255373 is about 277.0062556421.

The spelling of 21255373 in words is "twenty-one million, two hundred fifty-five thousand, three hundred seventy-three".