21231001213333 has 4 divisors (see below), whose sum is σ = 21232818792108. Its totient is φ = 21229183634560.

The previous prime is 21231001213327. The next prime is 21231001213343. The reversal of 21231001213333 is 33331210013212.

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 12727612786084 + 8503388427249 = 3567578^2 + 2916057^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21231001213333 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21231001213298 and 21231001213307.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21231001213343) 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, 908771866 + ... + 908795227.

It is an arithmetic number, because the mean of its divisors is an integer number (5308204698027).

Almost surely, 2^{21231001213333} is an apocalyptic number.

It is an amenable number.

21231001213333 is a deficient number, since it is larger than the sum of its proper divisors (1817578775).

21231001213333 is a wasteful number, since it uses less digits than its factorization.

21231001213333 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1817578774.

The product of its (nonzero) digits is 1944, while the sum is 25.

Adding to 21231001213333 its reverse (33331210013212), we get a palindrome (54562211226545).

The spelling of 21231001213333 in words is "twenty-one trillion, two hundred thirty-one billion, one million, two hundred thirteen thousand, three hundred thirty-three".