21110055 has 8 divisors (see below), whose sum is σ = 33776112. Its totient is φ = 11258688.

The previous prime is 21110051. The next prime is 21110071. The reversal of 21110055 is 55001112.

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

It is not a de Polignac number, because 21110055 - 2² = 21110051 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (15), and also a Moran number because the ratio is a prime number: 1407337 = 21110055 / (2 + 1 + 1 + 1 + 0 + 0 + 5 + 5).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21110051) 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, 703654 + ... + 703683.

It is an arithmetic number, because the mean of its divisors is an integer number (4222014).

Almost surely, 2^21110055 is an apocalyptic number.

21110055 is a deficient number, since it is larger than the sum of its proper divisors (12666057).

21110055 is a wasteful number, since it uses less digits than its factorization.

21110055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1407345.

The product of its (nonzero) digits is 50, while the sum is 15.

The square root of 21110055 is about 4594.5679883967. The cubic root of 21110055 is about 276.3735359247.

Adding to 21110055 its reverse (55001112), we get a palindrome (76111167).

The spelling of 21110055 in words is "twenty-one million, one hundred ten thousand, fifty-five".