21120120101 has 2 divisors, whose sum is σ = 21120120102. Its totient is φ = 21120120100.

The previous prime is 21120120089. The next prime is 21120120137. The reversal of 21120120101 is 10102102112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20236485025 + 883635076 = 142255^2 + 29726^2 .

It is a cyclic number.

It is not a de Polignac number, because 21120120101 - 2³⁰ = 20046378277 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21120125101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560060050 + 10560060051.

It is an arithmetic number, because the mean of its divisors is an integer number (10560060051).

Almost surely, 2^21120120101 is an apocalyptic number.

It is an amenable number.

21120120101 is a deficient number, since it is larger than the sum of its proper divisors (1).

21120120101 is an equidigital number, since it uses as much as digits as its factorization.

21120120101 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 21120120101 its reverse (10102102112), we get a palindrome (31222222213).

The spelling of 21120120101 in words is "twenty-one billion, one hundred twenty million, one hundred twenty thousand, one hundred one".