21551105104000 has 64 divisors (see below), whose sum is σ = 53581435104600. Its totient is φ = 8620442035200.

The previous prime is 21551105103991. The next prime is 21551105104049. The reversal of 21551105104000 is 40150115512.

It can be written as a sum of positive squares in 4 ways, for example, as 13365692551744 + 8185412552256 = 3655912^2 + 2861016^2 .

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (25).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 673456035 + ... + 673488034.

Almost surely, 2^{21551105104000} is an apocalyptic number.

21551105104000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21551105104000 is an abundant number, since it is smaller than the sum of its proper divisors (32030330000600).

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

21551105104000 is an equidigital number, since it uses as much as digits as its factorization.

21551105104000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1346944098 (or 1346944076 counting only the distinct ones).

The product of its (nonzero) digits is 1000, while the sum is 25.

Adding to 21551105104000 its reverse (40150115512), we get a palindrome (21591255219512).

The spelling of 21551105104000 in words is "twenty-one trillion, five hundred fifty-one billion, one hundred five million, one hundred four thousand".