21536085097644 has 96 divisors (see below), whose sum is σ = 54727183896000. Its totient is φ = 6551819993088.

The previous prime is 21536085097613. The next prime is 21536085097661. The reversal of 21536085097644 is 44679058063512.

It is a happy number.

It is a super-2 number, since 2×21536085097644² (a number of 27 digits) contains 22 as substring.

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 31 ways as a sum of consecutive naturals, for example, 14942482 + ... + 16320230.

It is an arithmetic number, because the mean of its divisors is an integer number (570074832250).

It is a 1-persistent number, because it is pandigital, but 2⋅21536085097644 = 43072170195288 is not.

Almost surely, 2^{21536085097644} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21536085097644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27363591948000).

21536085097644 is an abundant number, since it is smaller than the sum of its proper divisors (33191098798356).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21536085097644 is a wasteful number, since it uses less digits than its factorization.

21536085097644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1378899 (or 1378897 counting only the distinct ones).

The product of its (nonzero) digits is 43545600, while the sum is 60.

The spelling of 21536085097644 in words is "twenty-one trillion, five hundred thirty-six billion, eighty-five million, ninety-seven thousand, six hundred forty-four".