21000110012261 has 2 divisors, whose sum is σ = 21000110012262. Its totient is φ = 21000110012260.

The previous prime is 21000110012249. The next prime is 21000110012267. The reversal of 21000110012261 is 16221001100012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20535489192100 + 464620820161 = 4531610^2 + 681631^2 .

It is a cyclic number.

It is not a de Polignac number, because 21000110012261 - 2⁶ = 21000110012197 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21000110012267) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500055006130 + 10500055006131.

It is an arithmetic number, because the mean of its divisors is an integer number (10500055006131).

Almost surely, 2^{21000110012261} is an apocalyptic number.

It is an amenable number.

21000110012261 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000110012261 is an equidigital number, since it uses as much as digits as its factorization.

21000110012261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48, while the sum is 17.

Adding to 21000110012261 its reverse (16221001100012), we get a palindrome (37221111112273).

The spelling of 21000110012261 in words is "twenty-one trillion, one hundred ten million, twelve thousand, two hundred sixty-one".