21313323123021 has 12 divisors (see below), whose sum is σ = 30859036862940. Its totient is φ = 14175131765760.

The previous prime is 21313323123017. The next prime is 21313323123061. The reversal of 21313323123021 is 12032132331312.

21313323123021 is a `hidden beast` number, since 2 + 1 + 3 + 13 + 32 + 312 + 302 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 5711502515625 + 15601820607396 = 2389875^2 + 3949914^2 .

It is not a de Polignac number, because 21313323123021 - 2² = 21313323123017 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21313323123061) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2812522356 + ... + 2812529933.

It is an arithmetic number, because the mean of its divisors is an integer number (2571586405245).

Almost surely, 2^{21313323123021} is an apocalyptic number.

It is an amenable number.

21313323123021 is a deficient number, since it is larger than the sum of its proper divisors (9545713739919).

21313323123021 is a wasteful number, since it uses less digits than its factorization.

21313323123021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5625052716 (or 5625052713 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 27.

Adding to 21313323123021 its reverse (12032132331312), we get a palindrome (33345455454333).

The spelling of 21313323123021 in words is "twenty-one trillion, three hundred thirteen billion, three hundred twenty-three million, one hundred twenty-three thousand, twenty-one".