21500543355 has 16 divisors (see below), whose sum is σ = 36211441920. Its totient is φ = 10863432288.

The previous prime is 21500543333. The next prime is 21500543369. The reversal of 21500543355 is 55334500512.

It is a happy number.

It is not a de Polignac number, because 21500543355 - 2¹³ = 21500535163 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 37719967 + ... + 37720536.

It is an arithmetic number, because the mean of its divisors is an integer number (2263215120).

Almost surely, 2^21500543355 is an apocalyptic number.

21500543355 is a deficient number, since it is larger than the sum of its proper divisors (14710898565).

21500543355 is a wasteful number, since it uses less digits than its factorization.

21500543355 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75440530.

The product of its (nonzero) digits is 45000, while the sum is 33.

The spelling of 21500543355 in words is "twenty-one billion, five hundred million, five hundred forty-three thousand, three hundred fifty-five".