21604555531344 has 40 divisors (see below), whose sum is σ = 55822079817952. Its totient is φ = 7200188012160.

The previous prime is 21604555531343. The next prime is 21604555531379. The reversal of 21604555531344 is 44313555540612.

It is a happy number.

It is a super-3 number, since 3×21604555531344³ (a number of 41 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a junction number, because it is equal to n+sod(n) for n = 21604555531293 and 21604555531302.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21604555531343) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41315542 + ... + 41835189.

Almost surely, 2^{21604555531344} is an apocalyptic number.

21604555531344 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21604555531344 is an abundant number, since it is smaller than the sum of its proper divisors (34217524286608).

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

21604555531344 is a wasteful number, since it uses less digits than its factorization.

21604555531344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83156155 (or 83156149 counting only the distinct ones).

The product of its (nonzero) digits is 4320000, while the sum is 48.

The spelling of 21604555531344 in words is "twenty-one trillion, six hundred four billion, five hundred fifty-five million, five hundred thirty-one thousand, three hundred forty-four".