21231121333 has 2 divisors, whose sum is σ = 21231121334. Its totient is φ = 21231121332.

The previous prime is 21231121259. The next prime is 21231121349. The reversal of 21231121333 is 33312113212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20840387044 + 390734289 = 144362^2 + 19767^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21231121333 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21231121733) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615560666 + 10615560667.

It is an arithmetic number, because the mean of its divisors is an integer number (10615560667).

Almost surely, 2^21231121333 is an apocalyptic number.

It is an amenable number.

21231121333 is a deficient number, since it is larger than the sum of its proper divisors (1).

21231121333 is an equidigital number, since it uses as much as digits as its factorization.

21231121333 is an evil number, because the sum of its binary digits is even.

The product of its digits is 648, while the sum is 22.

Adding to 21231121333 its reverse (33312113212), we get a palindrome (54543234545).

The spelling of 21231121333 in words is "twenty-one billion, two hundred thirty-one million, one hundred twenty-one thousand, three hundred thirty-three".