21036169 has 16 divisors (see below), whose sum is σ = 26363520. Its totient is φ = 16306560.

The previous prime is 21036163. The next prime is 21036187. The reversal of 21036169 is 96163012.

21036169 = T₃₀₉ + T₃₁₀ + ... + T₅₃₇.

It is a cyclic number.

It is not a de Polignac number, because 21036169 - 2⁵ = 21036137 is a prime.

It is a super-2 number, since 2×21036169² = 885040812393122, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21036163) 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 15 ways as a sum of consecutive naturals, for example, 17037 + ... + 18229.

It is an arithmetic number, because the mean of its divisors is an integer number (1647720).

Almost surely, 2^21036169 is an apocalyptic number.

It is an amenable number.

21036169 is a deficient number, since it is larger than the sum of its proper divisors (5327351).

21036169 is a wasteful number, since it uses less digits than its factorization.

21036169 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1440.

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 21036169 is about 4586.5203586161. The cubic root of 21036169 is about 276.0507196923.

The spelling of 21036169 in words is "twenty-one million, thirty-six thousand, one hundred sixty-nine".