21667357241 has 2 divisors, whose sum is σ = 21667357242. Its totient is φ = 21667357240.

The previous prime is 21667357219. The next prime is 21667357297. The reversal of 21667357241 is 14275376612.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12759961600 + 8907395641 = 112960^2 + 94379^2 .

It is a cyclic number.

It is not a de Polignac number, because 21667357241 - 2¹⁸ = 21667095097 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21667357192 and 21667357201.

It is not a weakly prime, because it can be changed into another prime (21667357141) 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, 10833678620 + 10833678621.

It is an arithmetic number, because the mean of its divisors is an integer number (10833678621).

Almost surely, 2^21667357241 is an apocalyptic number.

It is an amenable number.

21667357241 is a deficient number, since it is larger than the sum of its proper divisors (1).

21667357241 is an equidigital number, since it uses as much as digits as its factorization.

21667357241 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 423360, while the sum is 44.

The spelling of 21667357241 in words is "twenty-one billion, six hundred sixty-seven million, three hundred fifty-seven thousand, two hundred forty-one".