21107775518 has 16 divisors (see below), whose sum is σ = 33526846080. Its totient is φ = 9932261376.

The previous prime is 21107775511. The next prime is 21107775551. The reversal of 21107775518 is 81557770112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21107775511) by changing a digit.

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, 696755 + ... + 726417.

It is an arithmetic number, because the mean of its divisors is an integer number (2095427880).

Almost surely, 2^21107775518 is an apocalyptic number.

21107775518 is a deficient number, since it is larger than the sum of its proper divisors (12419070562).

21107775518 is a wasteful number, since it uses less digits than its factorization.

21107775518 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50611.

The product of its (nonzero) digits is 137200, while the sum is 44.

The spelling of 21107775518 in words is "twenty-one billion, one hundred seven million, seven hundred seventy-five thousand, five hundred eighteen".