21423411 has 6 divisors (see below), whose sum is σ = 30944940. Its totient is φ = 14282268.

The previous prime is 21423403. The next prime is 21423421. The reversal of 21423411 is 11432412.

It is not a de Polignac number, because 21423411 - 2³ = 21423403 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21423421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1190181 + ... + 1190198.

It is an arithmetic number, because the mean of its divisors is an integer number (5157490).

Almost surely, 2^21423411 is an apocalyptic number.

21423411 is a deficient number, since it is larger than the sum of its proper divisors (9521529).

21423411 is a wasteful number, since it uses less digits than its factorization.

21423411 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2380385 (or 2380382 counting only the distinct ones).

The product of its digits is 192, while the sum is 18.

The square root of 21423411 is about 4628.5430753100. The cubic root of 21423411 is about 277.7343139048.

Adding to 21423411 its reverse (11432412), we get a palindrome (32855823).

Subtracting from 21423411 its reverse (11432412), we obtain a palindrome (9990999).

The spelling of 21423411 in words is "twenty-one million, four hundred twenty-three thousand, four hundred eleven".