21342345 has 16 divisors (see below), whose sum is σ = 34981632. Its totient is φ = 11104640.

The previous prime is 21342341. The next prime is 21342359. The reversal of 21342345 is 54324312.

It is not a de Polignac number, because 21342345 - 2² = 21342341 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21342341) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16737 + ... + 17966.

It is an arithmetic number, because the mean of its divisors is an integer number (2186352).

Almost surely, 2^21342345 is an apocalyptic number.

It is an amenable number.

21342345 is a deficient number, since it is larger than the sum of its proper divisors (13639287).

21342345 is a wasteful number, since it uses less digits than its factorization.

21342345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34752.

The product of its digits is 2880, while the sum is 24.

The square root of 21342345 is about 4619.7775920492. Note that the first 3 decimals coincide. The cubic root of 21342345 is about 277.3835563720.

Adding to 21342345 its reverse (54324312), we get a palindrome (75666657).

The spelling of 21342345 in words is "twenty-one million, three hundred forty-two thousand, three hundred forty-five".