21050255 has 8 divisors (see below), whose sum is σ = 25330272. Its totient is φ = 16793568.

The previous prime is 21050251. The next prime is 21050269. The reversal of 21050255 is 55205012.

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 21050255 - 2² = 21050251 is a prime.

It is a super-2 number, since 2×21050255² = 886226471130050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21050251) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3779 + ... + 7508.

It is an arithmetic number, because the mean of its divisors is an integer number (3166284).

Almost surely, 2^21050255 is an apocalyptic number.

21050255 is a deficient number, since it is larger than the sum of its proper divisors (4280017).

21050255 is a wasteful number, since it uses less digits than its factorization.

21050255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11665.

The product of its (nonzero) digits is 500, while the sum is 20.

The square root of 21050255 is about 4588.0556884153. The cubic root of 21050255 is about 276.1123212581.

Adding to 21050255 its reverse (55205012), we get a palindrome (76255267).

The spelling of 21050255 in words is "twenty-one million, fifty thousand, two hundred fifty-five".