21201211011001 has 16 divisors (see below), whose sum is σ = 25410484224000. Its totient is φ = 17295010772688.

The previous prime is 21201211010989. The next prime is 21201211011049. The reversal of 21201211011001 is 10011011210212.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21201211011001 - 2⁷ = 21201211010873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21201211011401) 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 15 ways as a sum of consecutive naturals, for example, 330833641 + ... + 330897718.

It is an arithmetic number, because the mean of its divisors is an integer number (1588155264000).

Almost surely, 2^{21201211011001} is an apocalyptic number.

It is an amenable number.

21201211011001 is a deficient number, since it is larger than the sum of its proper divisors (4209273212999).

21201211011001 is a wasteful number, since it uses less digits than its factorization.

21201211011001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 661731588.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21201211011001 its reverse (10011011210212), we get a palindrome (31212222221213).

The spelling of 21201211011001 in words is "twenty-one trillion, two hundred one billion, two hundred eleven million, eleven thousand, one".