21169371 has 4 divisors (see below), whose sum is σ = 28225832. Its totient is φ = 14112912.

The previous prime is 21169367. The next prime is 21169381. The reversal of 21169371 is 17396112.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21169371 - 2² = 21169367 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21169321) 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 3 ways as a sum of consecutive naturals, for example, 3528226 + ... + 3528231.

It is an arithmetic number, because the mean of its divisors is an integer number (7056458).

Almost surely, 2^21169371 is an apocalyptic number.

21169371 is a deficient number, since it is larger than the sum of its proper divisors (7056461).

21169371 is an equidigital number, since it uses as much as digits as its factorization.

21169371 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7056460.

The product of its digits is 2268, while the sum is 30.

The square root of 21169371 is about 4601.0184742076. The cubic root of 21169371 is about 276.6321495300.

The spelling of 21169371 in words is "twenty-one million, one hundred sixty-nine thousand, three hundred seventy-one".