21204463 has 8 divisors (see below), whose sum is σ = 24325920. Its totient is φ = 18106080.

The previous prime is 21204451. The next prime is 21204487. The reversal of 21204463 is 36440212.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21204463 - 2¹⁷ = 21073391 is a prime.

It is a super-2 number, since 2×21204463² = 899258502236738, 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 (21204493) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3748 + ... + 7513.

It is an arithmetic number, because the mean of its divisors is an integer number (3040740).

Almost surely, 2^21204463 is an apocalyptic number.

21204463 is a deficient number, since it is larger than the sum of its proper divisors (3121457).

21204463 is a wasteful number, since it uses less digits than its factorization.

21204463 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11537.

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 21204463 is about 4604.8303986140. The cubic root of 21204463 is about 276.7849208195.

Adding to 21204463 its reverse (36440212), we get a palindrome (57644675).

The spelling of 21204463 in words is "twenty-one million, two hundred four thousand, four hundred sixty-three".