21312310133 has 4 divisors (see below), whose sum is σ = 21313939968. Its totient is φ = 21310680300.

The previous prime is 21312310093. The next prime is 21312310153. The reversal of 21312310133 is 33101321312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21312310133 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21312310153) 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, 795143 + ... + 821508.

It is an arithmetic number, because the mean of its divisors is an integer number (5328484992).

Almost surely, 2^21312310133 is an apocalyptic number.

It is an amenable number.

21312310133 is a deficient number, since it is larger than the sum of its proper divisors (1629835).

21312310133 is a wasteful number, since it uses less digits than its factorization.

21312310133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1629834.

The product of its (nonzero) digits is 324, while the sum is 20.

Adding to 21312310133 its reverse (33101321312), we get a palindrome (54413631445).

The spelling of 21312310133 in words is "twenty-one billion, three hundred twelve million, three hundred ten thousand, one hundred thirty-three".