21153169 has 4 divisors (see below), whose sum is σ = 22072896. Its totient is φ = 20233444.

The previous prime is 21153163. The next prime is 21153199. The reversal of 21153169 is 96135112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21153169 - 2³ = 21153161 is a prime.

It is a super-2 number, since 2×21153169² = 894913117485122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21153161) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 459829 + ... + 459874.

It is an arithmetic number, because the mean of its divisors is an integer number (5518224).

Almost surely, 2^21153169 is an apocalyptic number.

It is an amenable number.

21153169 is a deficient number, since it is larger than the sum of its proper divisors (919727).

21153169 is an equidigital number, since it uses as much as digits as its factorization.

21153169 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 919726.

The product of its digits is 1620, while the sum is 28.

The square root of 21153169 is about 4599.2574400657. The cubic root of 21153169 is about 276.5615579506.

It can be divided in two parts, 211531 and 69, that added together give a square (211600 = 460²).

The spelling of 21153169 in words is "twenty-one million, one hundred fifty-three thousand, one hundred sixty-nine".