21147369 has 4 divisors (see below), whose sum is σ = 28196496. Its totient is φ = 14098244.

The previous prime is 21147353. The next prime is 21147383. The reversal of 21147369 is 96374112.

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 21147369 - 2⁴ = 21147353 is a prime.

It is a super-2 number, since 2×21147369² = 894422431244322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21147319) 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 3 ways as a sum of consecutive naturals, for example, 3524559 + ... + 3524564.

It is an arithmetic number, because the mean of its divisors is an integer number (7049124).

Almost surely, 2^21147369 is an apocalyptic number.

It is an amenable number.

21147369 is a deficient number, since it is larger than the sum of its proper divisors (7049127).

21147369 is an equidigital number, since it uses as much as digits as its factorization.

21147369 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7049126.

The product of its digits is 9072, while the sum is 33.

The square root of 21147369 is about 4598.6268602704. The cubic root of 21147369 is about 276.5362787806.

The spelling of 21147369 in words is "twenty-one million, one hundred forty-seven thousand, three hundred sixty-nine".