20011211111021 has 16 divisors (see below), whose sum is σ = 22837404688560. Its totient is φ = 17399927354880.

The previous prime is 20011211110951. The next prime is 20011211111027. The reversal of 20011211111021 is 12011111211002.

It can be written as a sum of positive squares in 8 ways, for example, as 7055451564100 + 12955759546921 = 2656210^2 + 3599411^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20011211111021 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20011211110987 and 20011211111005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20011211111027) 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, 647303270 + ... + 647334183.

It is an arithmetic number, because the mean of its divisors is an integer number (1427337793035).

Almost surely, 2^{20011211111021} is an apocalyptic number.

It is an amenable number.

20011211111021 is a deficient number, since it is larger than the sum of its proper divisors (2826193577539).

20011211111021 is a wasteful number, since it uses less digits than its factorization.

20011211111021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1294637536.

The product of its (nonzero) digits is 8, while the sum is 14.

Adding to 20011211111021 its reverse (12011111211002), we get a palindrome (32022322322023).

The spelling of 20011211111021 in words is "twenty trillion, eleven billion, two hundred eleven million, one hundred eleven thousand, twenty-one".