21544403354004 has 12 divisors (see below), whose sum is σ = 50270274492704. Its totient is φ = 7181467784664.

The previous prime is 21544403353987. The next prime is 21544403354021. The reversal of 21544403354004 is 40045330444512.

It is an interprime number because it is at equal distance from previous prime (21544403353987) and next prime (21544403354021).

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×21544403354004² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 897683473072 + ... + 897683473095.

Almost surely, 2^{21544403354004} is an apocalyptic number.

It is an amenable number.

21544403354004 is an abundant number, since it is smaller than the sum of its proper divisors (28725871138700).

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

21544403354004 is a wasteful number, since it uses less digits than its factorization.

21544403354004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1795366946174 (or 1795366946172 counting only the distinct ones).

The product of its (nonzero) digits is 460800, while the sum is 39.

Adding to 21544403354004 its reverse (40045330444512), we get a palindrome (61589733798516).

The spelling of 21544403354004 in words is "twenty-one trillion, five hundred forty-four billion, four hundred three million, three hundred fifty-four thousand, four".