20121220188 has 36 divisors (see below), whose sum is σ = 52102513008. Its totient is φ = 6543485760.

The previous prime is 20121220187. The next prime is 20121220241. The reversal of 20121220188 is 88102212102.

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20121220181) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6814656 + ... + 6817607.

It is an arithmetic number, because the mean of its divisors is an integer number (1447292028).

Almost surely, 2^20121220188 is an apocalyptic number.

It is an amenable number.

20121220188 is an abundant number, since it is smaller than the sum of its proper divisors (31981292820).

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

20121220188 is a wasteful number, since it uses less digits than its factorization.

20121220188 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13632314 (or 13632309 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 27.

The spelling of 20121220188 in words is "twenty billion, one hundred twenty-one million, two hundred twenty thousand, one hundred eighty-eight".