21100012120111 has 4 divisors (see below), whose sum is σ = 21168741801592. Its totient is φ = 21031282438632.

The previous prime is 21100012120097. The next prime is 21100012120133. The reversal of 21100012120111 is 11102121000112.

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 21100012120111 - 2⁵ = 21100012120079 is a prime.

It is a super-2 number, since 2×21100012120111² (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 = 21100012120091 and 21100012120100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21100012120181) 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, 34364840280 + ... + 34364840893.

It is an arithmetic number, because the mean of its divisors is an integer number (5292185450398).

Almost surely, 2^{21100012120111} is an apocalyptic number.

21100012120111 is a deficient number, since it is larger than the sum of its proper divisors (68729681481).

21100012120111 is an equidigital number, since it uses as much as digits as its factorization.

21100012120111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68729681480.

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

Adding to 21100012120111 its reverse (11102121000112), we get a palindrome (32202133120223).

The spelling of 21100012120111 in words is "twenty-one trillion, one hundred billion, twelve million, one hundred twenty thousand, one hundred eleven".