21433442131 has 4 divisors (see below), whose sum is σ = 21433811872. Its totient is φ = 21433072392.

The previous prime is 21433442111. The next prime is 21433442141. The reversal of 21433442131 is 13124433412.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21433442131 - 2⁵ = 21433442099 is a prime.

It is a super-2 number, since 2×21433442131² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21433442131.

It is not an unprimeable number, because it can be changed into a prime (21433442111) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 76896 + ... + 220861.

It is an arithmetic number, because the mean of its divisors is an integer number (5358452968).

Almost surely, 2^21433442131 is an apocalyptic number.

21433442131 is a deficient number, since it is larger than the sum of its proper divisors (369741).

21433442131 is an equidigital number, since it uses as much as digits as its factorization.

21433442131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 369740.

The product of its digits is 6912, while the sum is 28.

Adding to 21433442131 its reverse (13124433412), we get a palindrome (34557875543).

The spelling of 21433442131 in words is "twenty-one billion, four hundred thirty-three million, four hundred forty-two thousand, one hundred thirty-one".