21230142133 has 4 divisors (see below), whose sum is σ = 21230547660. Its totient is φ = 21229736608.

The previous prime is 21230142077. The next prime is 21230142163. The reversal of 21230142133 is 33124103212.

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

It can be written as a sum of positive squares in 2 ways, for example, as 3063954609 + 18166187524 = 55353^2 + 134782^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21230142133 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21230142163) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 110128 + ... + 233641.

It is an arithmetic number, because the mean of its divisors is an integer number (5307636915).

Almost surely, 2^21230142133 is an apocalyptic number.

It is an amenable number.

21230142133 is a deficient number, since it is larger than the sum of its proper divisors (405527).

21230142133 is an equidigital number, since it uses as much as digits as its factorization.

21230142133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 405526.

The product of its (nonzero) digits is 864, while the sum is 22.

Adding to 21230142133 its reverse (33124103212), we get a palindrome (54354245345).

The spelling of 21230142133 in words is "twenty-one billion, two hundred thirty million, one hundred forty-two thousand, one hundred thirty-three".