20011121500 has 48 divisors (see below), whose sum is σ = 43729489440. Its totient is φ = 7999833600.

The previous prime is 20011121491. The next prime is 20011121513. The reversal of 20011121500 is 512111002.

It is a congruent 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 15 ways as a sum of consecutive naturals, for example, 933907 + ... + 955093.

It is an arithmetic number, because the mean of its divisors is an integer number (911031030).

Almost surely, 2^20011121500 is an apocalyptic number.

20011121500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20011121500 is an abundant number, since it is smaller than the sum of its proper divisors (23718367940).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20011121500 is a wasteful number, since it uses less digits than its factorization.

20011121500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23095 (or 23083 counting only the distinct ones).

The product of its (nonzero) digits is 20, while the sum is 13.

Adding to 20011121500 its reverse (512111002), we get a palindrome (20523232502).

The spelling of 20011121500 in words is "twenty billion, eleven million, one hundred twenty-one thousand, five hundred".