21120120102101 has 4 divisors (see below), whose sum is σ = 21120165878604. Its totient is φ = 21120074325600.

The previous prime is 21120120102091. The next prime is 21120120102163. The reversal of 21120120102101 is 10120102102112.

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

It can be written as a sum of positive squares in 2 ways, for example, as 16252581039601 + 4867539062500 = 4031449^2 + 2206250^2 .

It is a cyclic number.

It is not a de Polignac number, because 21120120102101 - 2⁴² = 16722073590997 is a prime.

It is a super-2 number, since 2×21120120102101² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120120105101) 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, 22189070 + ... + 23121311.

It is an arithmetic number, because the mean of its divisors is an integer number (5280041469651).

Almost surely, 2^{21120120102101} is an apocalyptic number.

It is an amenable number.

21120120102101 is a deficient number, since it is larger than the sum of its proper divisors (45776503).

21120120102101 is an equidigital number, since it uses as much as digits as its factorization.

21120120102101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45776502.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21120120102101 its reverse (10120102102112), we get a palindrome (31240222204213).

The spelling of 21120120102101 in words is "twenty-one trillion, one hundred twenty billion, one hundred twenty million, one hundred two thousand, one hundred one".