21431433 has 8 divisors (see below), whose sum is σ = 28721088. Its totient is φ = 14214704.

The previous prime is 21431401. The next prime is 21431489. The reversal of 21431433 is 33413412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21431433 - 2⁵ = 21431401 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21431533) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17541 + ... + 18722.

It is an arithmetic number, because the mean of its divisors is an integer number (3590136).

Almost surely, 2^21431433 is an apocalyptic number.

It is an amenable number.

21431433 is a deficient number, since it is larger than the sum of its proper divisors (7289655).

21431433 is a wasteful number, since it uses less digits than its factorization.

21431433 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36463.

The product of its digits is 864, while the sum is 21.

The square root of 21431433 is about 4629.4095735850. The cubic root of 21431433 is about 277.7689754663.

Adding to 21431433 its reverse (33413412), we get a palindrome (54844845).

The spelling of 21431433 in words is "twenty-one million, four hundred thirty-one thousand, four hundred thirty-three".