21012121001011 has 6 divisors (see below), whose sum is σ = 24442671368580. Its totient is φ = 18010389429396.

The previous prime is 21012121000963. The next prime is 21012121001033. The reversal of 21012121001011 is 11010012121012.

It is a happy number.

It is not a de Polignac number, because 21012121001011 - 2³⁷ = 20874682047539 is a prime.

It is a super-2 number, since 2×21012121001011² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21012121000982 and 21012121001000.

It is not an unprimeable number, because it can be changed into a prime (21012121001611) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 214409397921 + ... + 214409398018.

It is an arithmetic number, because the mean of its divisors is an integer number (4073778561430).

Almost surely, 2^{21012121001011} is an apocalyptic number.

21012121001011 is a deficient number, since it is larger than the sum of its proper divisors (3430550367569).

21012121001011 is an equidigital number, since it uses as much as digits as its factorization.

21012121001011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 428818795953 (or 428818795946 counting only the distinct ones).

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

Adding to 21012121001011 its reverse (11010012121012), we get a palindrome (32022133122023).

The spelling of 21012121001011 in words is "twenty-one trillion, twelve billion, one hundred twenty-one million, one thousand, eleven".