21155055110 has 32 divisors (see below), whose sum is σ = 43552918080. Its totient is φ = 7247503872.

The previous prime is 21155055109. The next prime is 21155055113. The reversal of 21155055110 is 1155055112.

It is a super-2 number, since 2×21155055110² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21155055110.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21155055113) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26999 + ... + 207458.

It is an arithmetic number, because the mean of its divisors is an integer number (1361028690).

Almost surely, 2^21155055110 is an apocalyptic number.

21155055110 is an abundant number, since it is smaller than the sum of its proper divisors (22397862970).

21155055110 is a wasteful number, since it uses less digits than its factorization.

21155055110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 235760.

The product of its (nonzero) digits is 1250, while the sum is 26.

The spelling of 21155055110 in words is "twenty-one billion, one hundred fifty-five million, fifty-five thousand, one hundred ten".