21115535553342 has 64 divisors (see below), whose sum is σ = 47609808652800. Its totient is φ = 6935658670080.

The previous prime is 21115535553319. The next prime is 21115535553353. The reversal of 21115535553342 is 24335553551112.

21115535553342 is a `hidden beast` number, since 2 + 1 + 1 + 1 + 5 + 53 + 5 + 553 + 3 + 42 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5683134 + ... + 8633022.

It is an arithmetic number, because the mean of its divisors is an integer number (743903260200).

Almost surely, 2^{21115535553342} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21115535553342, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23804904326400).

21115535553342 is an abundant number, since it is smaller than the sum of its proper divisors (26494273099458).

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

21115535553342 is a wasteful number, since it uses less digits than its factorization.

21115535553342 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2951838 (or 2951832 counting only the distinct ones).

The product of its digits is 1350000, while the sum is 45.

The spelling of 21115535553342 in words is "twenty-one trillion, one hundred fifteen billion, five hundred thirty-five million, five hundred fifty-three thousand, three hundred forty-two".