21121100202111 has 32 divisors (see below), whose sum is σ = 35597030988288. Its totient is φ = 10839697395840.

The previous prime is 21121100202109. The next prime is 21121100202173. The reversal of 21121100202111 is 11120200112112.

It is a happy number.

It is not a de Polignac number, because 21121100202111 - 2¹ = 21121100202109 is a prime.

It is a super-2 number, since 2×21121100202111² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121100200111) 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, 1045485405 + ... + 1045505606.

It is an arithmetic number, because the mean of its divisors is an integer number (1112407218384).

Almost surely, 2^{21121100202111} is an apocalyptic number.

21121100202111 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21121100202111 is a deficient number, since it is larger than the sum of its proper divisors (14475930786177).

21121100202111 is a wasteful number, since it uses less digits than its factorization.

21121100202111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2090991071.

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

Adding to 21121100202111 its reverse (11120200112112), we get a palindrome (32241300314223).

The spelling of 21121100202111 in words is "twenty-one trillion, one hundred twenty-one billion, one hundred million, two hundred two thousand, one hundred eleven".