21340349 has 4 divisors (see below), whose sum is σ = 21610560. Its totient is φ = 21070140.

The previous prime is 21340339. The next prime is 21340351. The reversal of 21340349 is 94304312.

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 21340349 - 2⁸ = 21340093 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21340339) 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, 134987 + ... + 135144.

It is an arithmetic number, because the mean of its divisors is an integer number (5402640).

Almost surely, 2^21340349 is an apocalyptic number.

It is an amenable number.

21340349 is a deficient number, since it is larger than the sum of its proper divisors (270211).

21340349 is an equidigital number, since it uses as much as digits as its factorization.

21340349 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 270210.

The product of its (nonzero) digits is 2592, while the sum is 26.

The square root of 21340349 is about 4619.5615592824. The cubic root of 21340349 is about 277.3749088555.

The spelling of 21340349 in words is "twenty-one million, three hundred forty thousand, three hundred forty-nine".