21043427 has 8 divisors (see below), whose sum is σ = 21603600. Its totient is φ = 20490624.

The previous prime is 21043423. The next prime is 21043441. The reversal of 21043427 is 72434012.

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 21043427 - 2² = 21043423 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21043423) 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, 4199 + ... + 7727.

It is an arithmetic number, because the mean of its divisors is an integer number (2700450).

Almost surely, 2^21043427 is an apocalyptic number.

21043427 is a deficient number, since it is larger than the sum of its proper divisors (560173).

21043427 is an equidigital number, since it uses as much as digits as its factorization.

21043427 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3685.

The product of its (nonzero) digits is 1344, while the sum is 23.

The square root of 21043427 is about 4587.3115220137. The cubic root of 21043427 is about 276.0824641565.

Adding to 21043427 its reverse (72434012), we get a palindrome (93477439).

The spelling of 21043427 in words is "twenty-one million, forty-three thousand, four hundred twenty-seven".