21003060181 has 2 divisors, whose sum is σ = 21003060182. Its totient is φ = 21003060180.

The previous prime is 21003060073. The next prime is 21003060209. The reversal of 21003060181 is 18106030012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18595685956 + 2407374225 = 136366^2 + 49065^2 .

It is a cyclic number.

It is not a de Polignac number, because 21003060181 - 2⁹ = 21003059669 is a prime.

It is a super-2 number, since 2×21003060181² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21003063181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10501530090 + 10501530091.

It is an arithmetic number, because the mean of its divisors is an integer number (10501530091).

Almost surely, 2^21003060181 is an apocalyptic number.

It is an amenable number.

21003060181 is a deficient number, since it is larger than the sum of its proper divisors (1).

21003060181 is an equidigital number, since it uses as much as digits as its factorization.

21003060181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 22.

Adding to 21003060181 its reverse (18106030012), we get a palindrome (39109090193).

The spelling of 21003060181 in words is "twenty-one billion, three million, sixty thousand, one hundred eighty-one".