21001102111009 has 2 divisors, whose sum is σ = 21001102111010. Its totient is φ = 21001102111008.

The previous prime is 21001102110991. The next prime is 21001102111091. The reversal of 21001102111009 is 90011120110012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12156574810384 + 8844527300625 = 3486628^2 + 2973975^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21001102111009 is a prime.

It is not a weakly prime, because it can be changed into another prime (21001102121009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500551055504 + 10500551055505.

It is an arithmetic number, because the mean of its divisors is an integer number (10500551055505).

Almost surely, 2^{21001102111009} is an apocalyptic number.

It is an amenable number.

21001102111009 is a deficient number, since it is larger than the sum of its proper divisors (1).

21001102111009 is an equidigital number, since it uses as much as digits as its factorization.

21001102111009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36, while the sum is 19.

The spelling of 21001102111009 in words is "twenty-one trillion, one billion, one hundred two million, one hundred eleven thousand, nine".