20011220211001 has 4 divisors (see below), whose sum is σ = 20145523702500. Its totient is φ = 19876916719504.

The previous prime is 20011220210983. The next prime is 20011220211023. The reversal of 20011220211001 is 10011202211002.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4602054657600 + 15409165553401 = 2145240^2 + 3925451^2 .

It is a cyclic number.

It is not a de Polignac number, because 20011220211001 - 2¹⁹ = 20011219686713 is a prime.

It is a super-2 number, since 2×20011220211001² (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 (20011220211601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 67151745526 + ... + 67151745823.

It is an arithmetic number, because the mean of its divisors is an integer number (5036380925625).

Almost surely, 2^{20011220211001} is an apocalyptic number.

It is an amenable number.

20011220211001 is a deficient number, since it is larger than the sum of its proper divisors (134303491499).

20011220211001 is a wasteful number, since it uses less digits than its factorization.

20011220211001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134303491498.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 20011220211001 its reverse (10011202211002), we get a palindrome (30022422422003).

The spelling of 20011220211001 in words is "twenty trillion, eleven billion, two hundred twenty million, two hundred eleven thousand, one".