21541135555 has 4 divisors (see below), whose sum is σ = 25849362672. Its totient is φ = 17232908440.

The previous prime is 21541135549. The next prime is 21541135589. The reversal of 21541135555 is 55553114512.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21541135555 - 2¹⁷ = 21541004483 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2154113551 + ... + 2154113560.

It is an arithmetic number, because the mean of its divisors is an integer number (6462340668).

Almost surely, 2^21541135555 is an apocalyptic number.

21541135555 is a deficient number, since it is larger than the sum of its proper divisors (4308227117).

21541135555 is an equidigital number, since it uses as much as digits as its factorization.

21541135555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4308227116.

The product of its digits is 75000, while the sum is 37.

The spelling of 21541135555 in words is "twenty-one billion, five hundred forty-one million, one hundred thirty-five thousand, five hundred fifty-five".