21020021213111 has 2 divisors, whose sum is σ = 21020021213112. Its totient is φ = 21020021213110.

The previous prime is 21020021213057. The next prime is 21020021213129. The reversal of 21020021213111 is 11131212002012.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21020021213111 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21020021213111.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21020021213131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510010606555 + 10510010606556.

It is an arithmetic number, because the mean of its divisors is an integer number (10510010606556).

Almost surely, 2^{21020021213111} is an apocalyptic number.

21020021213111 is a deficient number, since it is larger than the sum of its proper divisors (1).

21020021213111 is an equidigital number, since it uses as much as digits as its factorization.

21020021213111 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48, while the sum is 17.

Adding to 21020021213111 its reverse (11131212002012), we get a palindrome (32151233215123).

The spelling of 21020021213111 in words is "twenty-one trillion, twenty billion, twenty-one million, two hundred thirteen thousand, one hundred eleven".