21501555552055 has 32 divisors (see below), whose sum is σ = 27358683379200. Its totient is φ = 16166273925120.

The previous prime is 21501555552019. The next prime is 21501555552097. The reversal of 21501555552055 is 55025555510512.

It is not a de Polignac number, because 21501555552055 - 2⁹ = 21501555551543 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21501555551996 and 21501555552014.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 203250375 + ... + 203356135.

It is an arithmetic number, because the mean of its divisors is an integer number (854958855600).

Almost surely, 2^{21501555552055} is an apocalyptic number.

21501555552055 is a deficient number, since it is larger than the sum of its proper divisors (5857127827145).

21501555552055 is a wasteful number, since it uses less digits than its factorization.

21501555552055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109179.

The product of its (nonzero) digits is 1562500, while the sum is 46.

The spelling of 21501555552055 in words is "twenty-one trillion, five hundred one billion, five hundred fifty-five million, five hundred fifty-two thousand, fifty-five".