21611121344125 has 16 divisors (see below), whose sum is σ = 27065982235968. Its totient is φ = 17227805538000.

The previous prime is 21611121344123. The next prime is 21611121344177. The reversal of 21611121344125 is 52144312111612.

It is not a de Polignac number, because 21611121344125 - 2¹ = 21611121344123 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21611121344123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 305422171 + ... + 305492920.

It is an arithmetic number, because the mean of its divisors is an integer number (1691623889748).

Almost surely, 2^{21611121344125} is an apocalyptic number.

21611121344125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21611121344125 is a deficient number, since it is larger than the sum of its proper divisors (5454860891843).

21611121344125 is an equidigital number, since it uses as much as digits as its factorization.

21611121344125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 610915389 (or 610915379 counting only the distinct ones).

The product of its digits is 11520, while the sum is 34.

Adding to 21611121344125 its reverse (52144312111612), we get a palindrome (73755433455737).

The spelling of 21611121344125 in words is "twenty-one trillion, six hundred eleven billion, one hundred twenty-one million, three hundred forty-four thousand, one hundred twenty-five".