21404419 has 4 divisors (see below), whose sum is σ = 21926520. Its totient is φ = 20882320.

The previous prime is 21404417. The next prime is 21404437. The reversal of 21404419 is 91440412.

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

It is a cyclic number.

It is not a de Polignac number, because 21404419 - 2¹ = 21404417 is a prime.

It is a super-2 number, since 2×21404419² = 916298305455122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21404393 and 21404402.

It is not an unprimeable number, because it can be changed into a prime (21404413) 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, 260989 + ... + 261070.

It is an arithmetic number, because the mean of its divisors is an integer number (5481630).

Almost surely, 2^21404419 is an apocalyptic number.

21404419 is a deficient number, since it is larger than the sum of its proper divisors (522101).

21404419 is an equidigital number, since it uses as much as digits as its factorization.

21404419 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 522100.

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 21404419 is about 4626.4910029092. The cubic root of 21404419 is about 277.6522185193.

The spelling of 21404419 in words is "twenty-one million, four hundred four thousand, four hundred nineteen".