20021111212021 has 2 divisors, whose sum is σ = 20021111212022. Its totient is φ = 20021111212020.

The previous prime is 20021111211971. The next prime is 20021111212073. The reversal of 20021111212021 is 12021211112002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17855813676996 + 2165297535025 = 4225614^2 + 1471495^2 .

It is a cyclic number.

It is not a de Polignac number, because 20021111212021 - 2⁹ = 20021111211509 is a prime.

It is a super-2 number, since 2×20021111212021² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20021111211986 and 20021111212004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20021111212121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10010555606010 + 10010555606011.

It is an arithmetic number, because the mean of its divisors is an integer number (10010555606011).

Almost surely, 2^{20021111212021} is an apocalyptic number.

It is an amenable number.

20021111212021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20021111212021 is an equidigital number, since it uses as much as digits as its factorization.

20021111212021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 20021111212021 its reverse (12021211112002), we get a palindrome (32042322324023).

The spelling of 20021111212021 in words is "twenty trillion, twenty-one billion, one hundred eleven million, two hundred twelve thousand, twenty-one".