21120645320635 has 16 divisors (see below), whose sum is σ = 28965699219456. Its totient is φ = 14482606830048.

The previous prime is 21120645320611. The next prime is 21120645320639. The reversal of 21120645320635 is 53602354602112.

It is not a de Polignac number, because 21120645320635 - 2³³ = 21112055386043 is a prime.

It is a super-2 number, since 2×21120645320635² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21120645320639) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1811382 + ... + 6747028.

It is an arithmetic number, because the mean of its divisors is an integer number (1810356201216).

Almost surely, 2^{21120645320635} is an apocalyptic number.

21120645320635 is a deficient number, since it is larger than the sum of its proper divisors (7845053898821).

21120645320635 is a wasteful number, since it uses less digits than its factorization.

21120645320635 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5057922.

The product of its (nonzero) digits is 259200, while the sum is 40.

Adding to 21120645320635 its reverse (53602354602112), we get a palindrome (74722999922747).

The spelling of 21120645320635 in words is "twenty-one trillion, one hundred twenty billion, six hundred forty-five million, three hundred twenty thousand, six hundred thirty-five".