21106275 has 24 divisors (see below), whose sum is σ = 35039424. Its totient is φ = 11210400.

The previous prime is 21106259. The next prime is 21106277. The reversal of 21106275 is 57260112.

It is not a de Polignac number, because 21106275 - 2⁴ = 21106259 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21106277) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 25620 + ... + 26430.

It is an arithmetic number, because the mean of its divisors is an integer number (1459976).

Almost surely, 2^21106275 is an apocalyptic number.

21106275 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21106275 is a deficient number, since it is larger than the sum of its proper divisors (13933149).

21106275 is a wasteful number, since it uses less digits than its factorization.

21106275 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1171 (or 1166 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 24.

The square root of 21106275 is about 4594.1566146574. The cubic root of 21106275 is about 276.3570389785.

Adding to 21106275 its reverse (57260112), we get a palindrome (78366387).

It can be divided in two parts, 2110 and 6275, that added together give a triangular number (8385 = T₁₂₉).

The spelling of 21106275 in words is "twenty-one million, one hundred six thousand, two hundred seventy-five".