21432434 has 4 divisors (see below), whose sum is σ = 32148654. Its totient is φ = 10716216.

The previous prime is 21432413. The next prime is 21432443. The reversal of 21432434 is 43423412.

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

It can be written as a sum of positive squares in only one way, i.e., 16605625 + 4826809 = 4075^2 + 2197^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5358107 + ... + 5358110.

Almost surely, 2^21432434 is an apocalyptic number.

21432434 is a deficient number, since it is larger than the sum of its proper divisors (10716220).

21432434 is a wasteful number, since it uses less digits than its factorization.

21432434 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10716219.

The product of its digits is 2304, while the sum is 23.

The square root of 21432434 is about 4629.5176854614. The cubic root of 21432434 is about 277.7732999930.

Adding to 21432434 its reverse (43423412), we get a palindrome (64855846).

The spelling of 21432434 in words is "twenty-one million, four hundred thirty-two thousand, four hundred thirty-four".