21155002505050 has 12 divisors (see below), whose sum is σ = 39348304659486. Its totient is φ = 8462001002000.

The previous prime is 21155002505009. The next prime is 21155002505081. The reversal of 21155002505050 is 5050520055112.

It can be written as a sum of positive squares in 3 ways, for example, as 9316028615089 + 11838973889961 = 3052217^2 + 3440781^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 211550025001 + ... + 211550025100.

Almost surely, 2^{21155002505050} is an apocalyptic number.

21155002505050 is a deficient number, since it is larger than the sum of its proper divisors (18193302154436).

21155002505050 is a wasteful number, since it uses less digits than its factorization.

21155002505050 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 423100050113 (or 423100050108 counting only the distinct ones).

The product of its (nonzero) digits is 12500, while the sum is 31.

The spelling of 21155002505050 in words is "twenty-one trillion, one hundred fifty-five billion, two million, five hundred five thousand, fifty".