21342611 has 4 divisors (see below), whose sum is σ = 21486000. Its totient is φ = 21199224.

The previous prime is 21342583. The next prime is 21342631. The reversal of 21342611 is 11624312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21342611 - 2¹⁰ = 21341587 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21342631) 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, 71471 + ... + 71768.

It is an arithmetic number, because the mean of its divisors is an integer number (5371500).

Almost surely, 2^21342611 is an apocalyptic number.

21342611 is a deficient number, since it is larger than the sum of its proper divisors (143389).

21342611 is a wasteful number, since it uses less digits than its factorization.

21342611 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143388.

The product of its digits is 288, while the sum is 20.

The square root of 21342611 is about 4619.8063812242. The cubic root of 21342611 is about 277.3847087558.

Adding to 21342611 its reverse (11624312), we get a palindrome (32966923).

It can be divided in two parts, 213 and 42611, that added together give a palindrome (42824).

The spelling of 21342611 in words is "twenty-one million, three hundred forty-two thousand, six hundred eleven".