21001201101001 has 16 divisors (see below), whose sum is σ = 23124997605888. Its totient is φ = 18913343904000.

The previous prime is 21001201100993. The next prime is 21001201101011. The reversal of 21001201101001 is 10010110210012.

It is a cyclic number.

It is not a de Polignac number, because 21001201101001 - 2³ = 21001201100993 is a prime.

It is a super-2 number, since 2×21001201101001² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21001201101011) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1904886 + ... + 6755071.

It is an arithmetic number, because the mean of its divisors is an integer number (1445312350368).

Almost surely, 2^{21001201101001} is an apocalyptic number.

It is an amenable number.

21001201101001 is a deficient number, since it is larger than the sum of its proper divisors (2123796504887).

21001201101001 is a wasteful number, since it uses less digits than its factorization.

21001201101001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8662032.

The product of its (nonzero) digits is 4, while the sum is 10.

Adding to 21001201101001 its reverse (10010110210012), we get a palindrome (31011311311013).

The spelling of 21001201101001 in words is "twenty-one trillion, one billion, two hundred one million, one hundred one thousand, one".