21021012121011 has 32 divisors (see below), whose sum is σ = 32114643902976. Its totient is φ = 11981027520000.

The previous prime is 21021012121009. The next prime is 21021012121051. The reversal of 21021012121011 is 11012121012012.

It is a happy number.

It is not a de Polignac number, because 21021012121011 - 2¹ = 21021012121009 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21021012121051) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 104496756 + ... + 104697726.

It is an arithmetic number, because the mean of its divisors is an integer number (1003582621968).

Almost surely, 2^{21021012121011} is an apocalyptic number.

21021012121011 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21021012121011 is a deficient number, since it is larger than the sum of its proper divisors (11093631781965).

21021012121011 is a wasteful number, since it uses less digits than its factorization.

21021012121011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213803.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21021012121011 its reverse (11012121012012), we get a palindrome (32033133133023).

The spelling of 21021012121011 in words is "twenty-one trillion, twenty-one billion, twelve million, one hundred twenty-one thousand, eleven".