21085155433 has 2 divisors, whose sum is σ = 21085155434. Its totient is φ = 21085155432.

The previous prime is 21085155373. The next prime is 21085155457. The reversal of 21085155433 is 33455158012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20508531264 + 576624169 = 143208^2 + 24013^2 .

It is a cyclic number.

It is not a de Polignac number, because 21085155433 - 2⁹ = 21085154921 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21085155392 and 21085155401.

It is not a weakly prime, because it can be changed into another prime (21085155473) 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 as a sum of consecutive naturals, namely, 10542577716 + 10542577717.

It is an arithmetic number, because the mean of its divisors is an integer number (10542577717).

Almost surely, 2^21085155433 is an apocalyptic number.

It is an amenable number.

21085155433 is a deficient number, since it is larger than the sum of its proper divisors (1).

21085155433 is an equidigital number, since it uses as much as digits as its factorization.

21085155433 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72000, while the sum is 37.

The spelling of 21085155433 in words is "twenty-one billion, eighty-five million, one hundred fifty-five thousand, four hundred thirty-three".