21001101000181 has 2 divisors, whose sum is σ = 21001101000182. Its totient is φ = 21001101000180.

The previous prime is 21001101000107. The next prime is 21001101000223. The reversal of 21001101000181 is 18100010110012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20966929629156 + 34171371025 = 4578966^2 + 184855^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21001101000181 is a prime.

It is a super-2 number, since 2×21001101000181² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21001101006181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500550500090 + 10500550500091.

It is an arithmetic number, because the mean of its divisors is an integer number (10500550500091).

Almost surely, 2^{21001101000181} is an apocalyptic number.

It is an amenable number.

21001101000181 is a deficient number, since it is larger than the sum of its proper divisors (1).

21001101000181 is an equidigital number, since it uses as much as digits as its factorization.

21001101000181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 16.

Adding to 21001101000181 its reverse (18100010110012), we get a palindrome (39101111110193).

The spelling of 21001101000181 in words is "twenty-one trillion, one billion, one hundred one million, one hundred eighty-one", and thus it is an aban number.