20101221202001 has 4 divisors (see below), whose sum is σ = 20107076498532. Its totient is φ = 20095365905472.

The previous prime is 20101221201917. The next prime is 20101221202003. The reversal of 20101221202001 is 10020212210102.

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 4756765362001 + 15344455840000 = 2181001^2 + 3917200^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20101221202001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20101221202003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2927643116 + ... + 2927649981.

It is an arithmetic number, because the mean of its divisors is an integer number (5026769124633).

Almost surely, 2^{20101221202001} is an apocalyptic number.

It is an amenable number.

20101221202001 is a deficient number, since it is larger than the sum of its proper divisors (5855296531).

20101221202001 is an equidigital number, since it uses as much as digits as its factorization.

20101221202001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5855296530.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 20101221202001 its reverse (10020212210102), we get a palindrome (30121433412103).

It can be divided in two parts, 2010122 and 1202001, that added together give a palindrome (3212123).

The spelling of 20101221202001 in words is "twenty trillion, one hundred one billion, two hundred twenty-one million, two hundred two thousand, one".