21020311111121 has 16 divisors (see below), whose sum is σ = 24051336680448. Its totient is φ = 17996320680000.

The previous prime is 21020311111109. The next prime is 21020311111141. The reversal of 21020311111121 is 12111111302012.

It is a cyclic number.

It is not a de Polignac number, because 21020311111121 - 2⁶ = 21020311111057 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21020311111121.

It is not an unprimeable number, because it can be changed into a prime (21020311111141) 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, 62626496 + ... + 62961246.

It is an arithmetic number, because the mean of its divisors is an integer number (1503208542528).

Almost surely, 2^{21020311111121} is an apocalyptic number.

It is an amenable number.

21020311111121 is a deficient number, since it is larger than the sum of its proper divisors (3031025569327).

21020311111121 is an equidigital number, since it uses as much as digits as its factorization.

21020311111121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 345232.

The product of its (nonzero) digits is 24, while the sum is 17.

Adding to 21020311111121 its reverse (12111111302012), we get a palindrome (33131422413133).

The spelling of 21020311111121 in words is "twenty-one trillion, twenty billion, three hundred eleven million, one hundred eleven thousand, one hundred twenty-one".