21050711555 has 8 divisors (see below), whose sum is σ = 25412117472. Its totient is φ = 16739726848.

The previous prime is 21050711531. The next prime is 21050711569. The reversal of 21050711555 is 55511705012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21050711555 - 2¹⁰ = 21050710531 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 7 ways as a sum of consecutive naturals, for example, 12604382 + ... + 12606051.

It is an arithmetic number, because the mean of its divisors is an integer number (3176514684).

Almost surely, 2^21050711555 is an apocalyptic number.

21050711555 is a deficient number, since it is larger than the sum of its proper divisors (4361405917).

21050711555 is a wasteful number, since it uses less digits than its factorization.

21050711555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25210605.

The product of its (nonzero) digits is 8750, while the sum is 32.

The spelling of 21050711555 in words is "twenty-one billion, fifty million, seven hundred eleven thousand, five hundred fifty-five".