20111111988 has 48 divisors (see below), whose sum is σ = 52843284480. Its totient is φ = 5897685600.

The previous prime is 20111111981. The next prime is 20111112023. The reversal of 20111111988 is 88911111102.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20111111981) 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, 2453278 + ... + 2461461.

It is an arithmetic number, because the mean of its divisors is an integer number (1100901760).

Almost surely, 2^20111111988 is an apocalyptic number.

It is an amenable number.

20111111988 is an abundant number, since it is smaller than the sum of its proper divisors (32732172492).

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

20111111988 is a wasteful number, since it uses less digits than its factorization.

20111111988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4914788 (or 4914786 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 33.

The spelling of 20111111988 in words is "twenty billion, one hundred eleven million, one hundred eleven thousand, nine hundred eighty-eight".