21253235233 has 2 divisors, whose sum is σ = 21253235234. Its totient is φ = 21253235232.

The previous prime is 21253235183. The next prime is 21253235239. The reversal of 21253235233 is 33253235212.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20940405264 + 312829969 = 144708^2 + 17687^2 .

It is a cyclic number.

It is not a de Polignac number, because 21253235233 - 2⁹ = 21253234721 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21253235195 and 21253235204.

It is not a weakly prime, because it can be changed into another prime (21253235239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10626617616 + 10626617617.

It is an arithmetic number, because the mean of its divisors is an integer number (10626617617).

Almost surely, 2^21253235233 is an apocalyptic number.

It is an amenable number.

21253235233 is a deficient number, since it is larger than the sum of its proper divisors (1).

21253235233 is an equidigital number, since it uses as much as digits as its factorization.

21253235233 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 32400, while the sum is 31.

The spelling of 21253235233 in words is "twenty-one billion, two hundred fifty-three million, two hundred thirty-five thousand, two hundred thirty-three".