21126169 has 2 divisors, whose sum is σ = 21126170. Its totient is φ = 21126168.

The previous prime is 21126109. The next prime is 21126229. The reversal of 21126169 is 96162112.

It is a balanced prime because it is at equal distance from previous prime (21126109) and next prime (21126229).

It can be written as a sum of positive squares in only one way, i.e., 20976400 + 149769 = 4580^2 + 387^2 .

It is a cyclic number.

It is not a de Polignac number, because 21126169 - 2⁷ = 21126041 is a prime.

It is a super-2 number, since 2×21126169² = 892630033233122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21126109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10563084 + 10563085.

It is an arithmetic number, because the mean of its divisors is an integer number (10563085).

Almost surely, 2^21126169 is an apocalyptic number.

It is an amenable number.

21126169 is a deficient number, since it is larger than the sum of its proper divisors (1).

21126169 is an equidigital number, since it uses as much as digits as its factorization.

21126169 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1296, while the sum is 28.

The square root of 21126169 is about 4596.3212463882. The cubic root of 21126169 is about 276.4438397124.

It can be divided in two parts, 2112 and 6169, that added together give a square (8281 = 91²).

The spelling of 21126169 in words is "twenty-one million, one hundred twenty-six thousand, one hundred sixty-nine".