21001000120001 has 8 divisors (see below), whose sum is σ = 22910345920800. Its totient is φ = 19091681647840.

The previous prime is 21001000119977. The next prime is 21001000120019. The reversal of 21001000120001 is 10002100010012.

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 21001000120001 - 2⁴² = 16602953608897 is a prime.

It is a super-3 number, since 3×21001000120001³ (a number of 41 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21001000120021) 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 in 7 ways as a sum of consecutive naturals, for example, 5208596 + ... + 8314533.

It is an arithmetic number, because the mean of its divisors is an integer number (2863793240100).

Almost surely, 2^{21001000120001} is an apocalyptic number.

It is an amenable number.

21001000120001 is a deficient number, since it is larger than the sum of its proper divisors (1909345800799).

21001000120001 is a wasteful number, since it uses less digits than its factorization.

21001000120001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13664319.

The product of its (nonzero) digits is 4, while the sum is 8.

Adding to 21001000120001 its reverse (10002100010012), we get a palindrome (31003100130013).

The spelling of 21001000120001 in words is "twenty-one trillion, one billion, one hundred twenty thousand, one".