21311433 has 48 divisors (see below), whose sum is σ = 37477440. Its totient is φ = 11491200.

The previous prime is 21311429. The next prime is 21311443. The reversal of 21311433 is 33411312.

It is not a de Polignac number, because 21311433 - 2² = 21311429 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21311413) 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 47 ways as a sum of consecutive naturals, for example, 37038 + ... + 37608.

It is an arithmetic number, because the mean of its divisors is an integer number (780780).

Almost surely, 2^21311433 is an apocalyptic number.

It is an amenable number.

21311433 is a deficient number, since it is larger than the sum of its proper divisors (16166007).

21311433 is a wasteful number, since it uses less digits than its factorization.

21311433 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 630 (or 627 counting only the distinct ones).

The product of its digits is 216, while the sum is 18.

The square root of 21311433 is about 4616.4307641294. The cubic root of 21311433 is about 277.2495719769.

Adding to 21311433 its reverse (33411312), we get a palindrome (54722745).

The spelling of 21311433 in words is "twenty-one million, three hundred eleven thousand, four hundred thirty-three".