21801306049 has 2 divisors, whose sum is σ = 21801306050. Its totient is φ = 21801306048.

The previous prime is 21801306001. The next prime is 21801306071. The reversal of 21801306049 is 94060310812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11266336449 + 10534969600 = 106143^2 + 102640^2 .

It is a cyclic number.

It is not a de Polignac number, because 21801306049 - 2⁷ = 21801305921 is a prime.

It is not a weakly prime, because it can be changed into another prime (21801306349) 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, 10900653024 + 10900653025.

It is an arithmetic number, because the mean of its divisors is an integer number (10900653025).

Almost surely, 2^21801306049 is an apocalyptic number.

It is an amenable number.

21801306049 is a deficient number, since it is larger than the sum of its proper divisors (1).

21801306049 is an equidigital number, since it uses as much as digits as its factorization.

21801306049 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368, while the sum is 34.

The spelling of 21801306049 in words is "twenty-one billion, eight hundred one million, three hundred six thousand, forty-nine".