21183421 has 4 divisors (see below), whose sum is σ = 24209632. Its totient is φ = 18157212.

The previous prime is 21183389. The next prime is 21183431. The reversal of 21183421 is 12438112.

It is a happy number.

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 21183421 - 2⁵ = 21183389 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21183392 and 21183401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21183431) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1513095 + ... + 1513108.

It is an arithmetic number, because the mean of its divisors is an integer number (6052408).

Almost surely, 2^21183421 is an apocalyptic number.

It is an amenable number.

21183421 is a deficient number, since it is larger than the sum of its proper divisors (3026211).

21183421 is an equidigital number, since it uses as much as digits as its factorization.

21183421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3026210.

The product of its digits is 384, while the sum is 22.

The square root of 21183421 is about 4602.5450568137. The cubic root of 21183421 is about 276.6933357624.

The spelling of 21183421 in words is "twenty-one million, one hundred eighty-three thousand, four hundred twenty-one".