21120010100021 has 8 divisors (see below), whose sum is σ = 24144116399040. Its totient is φ = 18097644300768.

The previous prime is 21120010099957. The next prime is 21120010100053. The reversal of 21120010100021 is 12000101002112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21120010100021 - 2⁶ = 21120010099957 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21120010099975 and 21120010100011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120010100071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 435098936 + ... + 435147473.

It is an arithmetic number, because the mean of its divisors is an integer number (3018014549880).

Almost surely, 2^{21120010100021} is an apocalyptic number.

It is an amenable number.

21120010100021 is a deficient number, since it is larger than the sum of its proper divisors (3024106299019).

21120010100021 is an equidigital number, since it uses as much as digits as its factorization.

21120010100021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 870249883.

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

Adding to 21120010100021 its reverse (12000101002112), we get a palindrome (33120111102133).

The spelling of 21120010100021 in words is "twenty-one trillion, one hundred twenty billion, ten million, one hundred thousand, twenty-one".