21101202121011 has 4 divisors (see below), whose sum is σ = 28134936161352. Its totient is φ = 14067468080672.

The previous prime is 21101202121009. The next prime is 21101202121019. The reversal of 21101202121011 is 11012120210112.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21101202121011 - 2¹ = 21101202121009 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21101202121019) 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, 3516867020166 + ... + 3516867020171.

It is an arithmetic number, because the mean of its divisors is an integer number (7033734040338).

Almost surely, 2^{21101202121011} is an apocalyptic number.

21101202121011 is a deficient number, since it is larger than the sum of its proper divisors (7033734040341).

21101202121011 is an equidigital number, since it uses as much as digits as its factorization.

21101202121011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7033734040340.

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

Adding to 21101202121011 its reverse (11012120210112), we get a palindrome (32113322331123).

The spelling of 21101202121011 in words is "twenty-one trillion, one hundred one billion, two hundred two million, one hundred twenty-one thousand, eleven".