21120107 has 4 divisors (see below), whose sum is σ = 21215040. Its totient is φ = 21025176.

The previous prime is 21120089. The next prime is 21120109. The reversal of 21120107 is 70102112.

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 21120107 - 2¹⁴ = 21103723 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21120091 and 21120100.

It is not an unprimeable number, because it can be changed into a prime (21120109) 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, 47132 + ... + 47577.

It is an arithmetic number, because the mean of its divisors is an integer number (5303760).

Almost surely, 2^21120107 is an apocalyptic number.

21120107 is a deficient number, since it is larger than the sum of its proper divisors (94933).

21120107 is an equidigital number, since it uses as much as digits as its factorization.

21120107 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94932.

The product of its (nonzero) digits is 28, while the sum is 14.

The square root of 21120107 is about 4595.6617586589. The cubic root of 21120107 is about 276.4173960022.

Adding to 21120107 its reverse (70102112), we get a palindrome (91222219).

The spelling of 21120107 in words is "twenty-one million, one hundred twenty thousand, one hundred seven".