21035155 has 4 divisors (see below), whose sum is σ = 25242192. Its totient is φ = 16828120.

The previous prime is 21035149. The next prime is 21035159. The reversal of 21035155 is 55153012.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21035155 - 2⁵ = 21035123 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21035159) 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 3 ways as a sum of consecutive naturals, for example, 2103511 + ... + 2103520.

It is an arithmetic number, because the mean of its divisors is an integer number (6310548).

Almost surely, 2^21035155 is an apocalyptic number.

21035155 is a deficient number, since it is larger than the sum of its proper divisors (4207037).

21035155 is an equidigital number, since it uses as much as digits as its factorization.

21035155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4207036.

The product of its (nonzero) digits is 750, while the sum is 22.

The square root of 21035155 is about 4586.4098159672. The cubic root of 21035155 is about 276.0462841584.

Adding to 21035155 its reverse (55153012), we get a palindrome (76188167).

The spelling of 21035155 in words is "twenty-one million, thirty-five thousand, one hundred fifty-five".