21553123442500 has 120 divisors (see below), whose sum is σ = 51590039371640. Its totient is φ = 7827615360000.

The previous prime is 21553123442497. The next prime is 21553123442509. The reversal of 21553123442500 is 524432135512.

It is a happy number.

It can be written as a sum of positive squares in 20 ways, for example, as 16555654250496 + 4997469192004 = 4068864^2 + 2235502^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21553123442500.

It is not an unprimeable number, because it can be changed into a prime (21553123442509) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 3453345 + ... + 7418344.

Almost surely, 2^{21553123442500} is an apocalyptic number.

21553123442500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21553123442500 is an abundant number, since it is smaller than the sum of its proper divisors (30036915929140).

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

21553123442500 is a wasteful number, since it uses less digits than its factorization.

21553123442500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10871787 (or 10871770 counting only the distinct ones).

The product of its (nonzero) digits is 144000, while the sum is 37.

The spelling of 21553123442500 in words is "twenty-one trillion, five hundred fifty-three billion, one hundred twenty-three million, four hundred forty-two thousand, five hundred".