21711275 has 6 divisors (see below), whose sum is σ = 26922012. Its totient is φ = 17369000.

The previous prime is 21711271. The next prime is 21711289. The reversal of 21711275 is 57211712.

It is not a de Polignac number, because 21711275 - 2² = 21711271 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21711271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 434201 + ... + 434250.

It is an arithmetic number, because the mean of its divisors is an integer number (4487002).

Almost surely, 2^21711275 is an apocalyptic number.

21711275 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21711275 is a deficient number, since it is larger than the sum of its proper divisors (5210737).

21711275 is an equidigital number, since it uses as much as digits as its factorization.

21711275 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 868461 (or 868456 counting only the distinct ones).

The product of its digits is 980, while the sum is 26.

The square root of 21711275 is about 4659.5359210977. The cubic root of 21711275 is about 278.9727452040.

Adding to 21711275 its reverse (57211712), we get a palindrome (78922987).

The spelling of 21711275 in words is "twenty-one million, seven hundred eleven thousand, two hundred seventy-five".