21143432 has 8 divisors (see below), whose sum is σ = 39643950. Its totient is φ = 10571712.

The previous prime is 21143411. The next prime is 21143453. The reversal of 21143432 is 23434112.

It is an interprime number because it is at equal distance from previous prime (21143411) and next prime (21143453).

It can be written as a sum of positive squares in only one way, i.e., 11195716 + 9947716 = 3346^2 + 3154^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1321457 + ... + 1321472.

Almost surely, 2^21143432 is an apocalyptic number.

It is an amenable number.

21143432 is a deficient number, since it is larger than the sum of its proper divisors (18500518).

21143432 is a wasteful number, since it uses less digits than its factorization.

21143432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2642935 (or 2642931 counting only the distinct ones).

The product of its digits is 576, while the sum is 20.

The square root of 21143432 is about 4598.1987777824. The cubic root of 21143432 is about 276.5191168206.

Adding to 21143432 its reverse (23434112), we get a palindrome (44577544).

The spelling of 21143432 in words is "twenty-one million, one hundred forty-three thousand, four hundred thirty-two".