21121201101 has 128 divisors (see below), whose sum is σ = 39179169792. Its totient is φ = 9848044800.

The previous prime is 21121201099. The next prime is 21121201109. The reversal of 21121201101 is 10110212112.

It is not a de Polignac number, because 21121201101 - 2¹ = 21121201099 is a prime.

It is a super-2 number, since 2×21121201101² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121201109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 13443646 + ... + 13445216.

It is an arithmetic number, because the mean of its divisors is an integer number (306087264).

Almost surely, 2^21121201101 is an apocalyptic number.

21121201101 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21121201101 is a deficient number, since it is larger than the sum of its proper divisors (18057968691).

21121201101 is a wasteful number, since it uses less digits than its factorization.

21121201101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1664 (or 1642 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21121201101 its reverse (10110212112), we get a palindrome (31231413213).

It can be divided in two parts, 21121 and 201101, that added together give a palindrome (222222).

The spelling of 21121201101 in words is "twenty-one billion, one hundred twenty-one million, two hundred one thousand, one hundred one".