21001100212001 has 16 divisors (see below), whose sum is σ = 26211557369088. Its totient is φ = 16382223345600.

The previous prime is 21001100211989. The next prime is 21001100212033. The reversal of 21001100212001 is 10021200110012.

It is a de Polignac number, because none of the positive numbers 2^k-21001100212001 is a prime.

It is a super-2 number, since 2×21001100212001² (a number of 27 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21001100212091) 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, 1625214110 + ... + 1625227031.

It is an arithmetic number, because the mean of its divisors is an integer number (1638222335568).

Almost surely, 2^{21001100212001} is an apocalyptic number.

It is an amenable number.

21001100212001 is a deficient number, since it is larger than the sum of its proper divisors (5210457157087).

21001100212001 is a wasteful number, since it uses less digits than its factorization.

21001100212001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3250441232.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 21001100212001 its reverse (10021200110012), we get a palindrome (31022300322013).

The spelling of 21001100212001 in words is "twenty-one trillion, one billion, one hundred million, two hundred twelve thousand, one".