21421339 has 8 divisors (see below), whose sum is σ = 22025952. Its totient is φ = 20825280.

The previous prime is 21421333. The next prime is 21421373. The reversal of 21421339 is 93312412.

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 21421339 - 2⁹ = 21420827 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21421333) 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, 3117 + ... + 7249.

It is an arithmetic number, because the mean of its divisors is an integer number (2753244).

Almost surely, 2^21421339 is an apocalyptic number.

21421339 is a deficient number, since it is larger than the sum of its proper divisors (604613).

21421339 is an equidigital number, since it uses as much as digits as its factorization.

21421339 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4277.

The product of its digits is 1296, while the sum is 25.

The square root of 21421339 is about 4628.3192413661. The cubic root of 21421339 is about 277.7253597743.

It can be divided in two parts, 2142 and 1339, that added together give a square (3481 = 59²).

The spelling of 21421339 in words is "twenty-one million, four hundred twenty-one thousand, three hundred thirty-nine".