21010001001091 has 2 divisors, whose sum is σ = 21010001001092. Its totient is φ = 21010001001090.

The previous prime is 21010001001083. The next prime is 21010001001113. The reversal of 21010001001091 is 19010010001012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21010001001091 - 2³ = 21010001001083 is a prime.

It is not a weakly prime, because it can be changed into another prime (21010001401091) 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, 10505000500545 + 10505000500546.

It is an arithmetic number, because the mean of its divisors is an integer number (10505000500546).

Almost surely, 2^{21010001001091} is an apocalyptic number.

21010001001091 is a deficient number, since it is larger than the sum of its proper divisors (1).

21010001001091 is an equidigital number, since it uses as much as digits as its factorization.

21010001001091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18, while the sum is 16.

The spelling of 21010001001091 in words is "twenty-one trillion, ten billion, one million, one thousand, ninety-one".