21001010100001 has 8 divisors (see below), whose sum is σ = 21725233929000. Its totient is φ = 20276789675520.

The previous prime is 21001010099963. The next prime is 21001010100023. The reversal of 21001010100001 is 10000101010012.

It can be written as a sum of positive squares in 4 ways, for example, as 700795008225 + 20300215091776 = 837135^2 + 4505576^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21001010100001 - 2¹¹ = 21001010097953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21001010100101) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23815281 + ... + 24681361.

It is an arithmetic number, because the mean of its divisors is an integer number (2715654241125).

Almost surely, 2^{21001010100001} is an apocalyptic number.

It is an amenable number.

21001010100001 is a deficient number, since it is larger than the sum of its proper divisors (724223828999).

21001010100001 is an equidigital number, since it uses as much as digits as its factorization.

21001010100001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1702259.

The product of its (nonzero) digits is 2, while the sum is 7.

Adding to 21001010100001 its reverse (10000101010012), we get a palindrome (31001111110013).

The spelling of 21001010100001 in words is "twenty-one trillion, one billion, ten million, one hundred thousand, one".