21120561020775 has 24 divisors (see below), whose sum is σ = 36045757479424. Its totient is φ = 10900934719200.

The previous prime is 21120561020771. The next prime is 21120561020831. The reversal of 21120561020775 is 57702016502112.

It is not a de Polignac number, because 21120561020775 - 2² = 21120561020771 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120561020771) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4542053809 + ... + 4542058458.

Almost surely, 2^{21120561020775} is an apocalyptic number.

21120561020775 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21120561020775 is a deficient number, since it is larger than the sum of its proper divisors (14925196458649).

21120561020775 is a wasteful number, since it uses less digits than its factorization.

21120561020775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9084112311 (or 9084112306 counting only the distinct ones).

The product of its (nonzero) digits is 58800, while the sum is 39.

Adding to 21120561020775 its reverse (57702016502112), we get a palindrome (78822577522887).

The spelling of 21120561020775 in words is "twenty-one trillion, one hundred twenty billion, five hundred sixty-one million, twenty thousand, seven hundred seventy-five".