21010012121011 has 4 divisors (see below), whose sum is σ = 21010021372224. Its totient is φ = 21010002869800.

The previous prime is 21010012120949. The next prime is 21010012121017. The reversal of 21010012121011 is 11012121001012.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21010012121011 - 2⁷ = 21010012120883 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21010012120982 and 21010012121000.

It is not an unprimeable number, because it can be changed into a prime (21010012121017) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1380606 + ... + 6627676.

It is an arithmetic number, because the mean of its divisors is an integer number (5252505343056).

Almost surely, 2^{21010012121011} is an apocalyptic number.

21010012121011 is a deficient number, since it is larger than the sum of its proper divisors (9251213).

21010012121011 is an equidigital number, since it uses as much as digits as its factorization.

21010012121011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9251212.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21010012121011 its reverse (11012121001012), we get a palindrome (32022133122023).

The spelling of 21010012121011 in words is "twenty-one trillion, ten billion, twelve million, one hundred twenty-one thousand, eleven".