21204469 has 16 divisors (see below), whose sum is σ = 25240320. Its totient is φ = 17559360.

The previous prime is 21204451. The next prime is 21204487. The reversal of 21204469 is 96440212.

It is an interprime number because it is at equal distance from previous prime (21204451) and next prime (21204487).

It is not a de Polignac number, because 21204469 - 2¹¹ = 21202421 is a prime.

It is a super-2 number, since 2×21204469² = 899259011143922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21204419) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10359 + ... + 12235.

It is an arithmetic number, because the mean of its divisors is an integer number (1577520).

Almost surely, 2^21204469 is an apocalyptic number.

It is an amenable number.

21204469 is a deficient number, since it is larger than the sum of its proper divisors (4035851).

21204469 is a wasteful number, since it uses less digits than its factorization.

21204469 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1980.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 21204469 is about 4604.8310501038. The cubic root of 21204469 is about 276.7849469258.

The spelling of 21204469 in words is "twenty-one million, two hundred four thousand, four hundred sixty-nine".