21611121643624 has 16 divisors (see below), whose sum is σ = 40523944349700. Its totient is φ = 10804736483712.

The previous prime is 21611121643607. The next prime is 21611121643649. The reversal of 21611121643624 is 42634612111612.

It can be written as a sum of positive squares in 2 ways, for example, as 20401319635524 + 1209802008100 = 4516782^2 + 1099910^2 .

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 102930837 + ... + 103140580.

Almost surely, 2^{21611121643624} is an apocalyptic number.

It is an amenable number.

21611121643624 is a deficient number, since it is larger than the sum of its proper divisors (18912822706076).

21611121643624 is a wasteful number, since it uses less digits than its factorization.

21611121643624 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 206084532 (or 206084528 counting only the distinct ones).

The product of its digits is 82944, while the sum is 40.

The spelling of 21611121643624 in words is "twenty-one trillion, six hundred eleven billion, one hundred twenty-one million, six hundred forty-three thousand, six hundred twenty-four".