20111121100 has 72 divisors (see below), whose sum is σ = 50134339808. Its totient is φ = 6859468800.

The previous prime is 20111121097. The next prime is 20111121103. The reversal of 20111121100 is 112111102.

It is an interprime number because it is at equal distance from previous prime (20111121097) and next prime (20111121103).

It is a Harshad number since it is a multiple of its sum of digits (10).

It is not an unprimeable number, because it can be changed into a prime (20111121103) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 60670 + ... + 209530.

Almost surely, 2^20111121100 is an apocalyptic number.

20111121100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20111121100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25067169904).

20111121100 is an abundant number, since it is smaller than the sum of its proper divisors (30023218708).

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

20111121100 is a wasteful number, since it uses less digits than its factorization.

20111121100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149075 (or 149068 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 10.

Adding to 20111121100 its reverse (112111102), we get a palindrome (20223232202).

The spelling of 20111121100 in words is "twenty billion, one hundred eleven million, one hundred twenty-one thousand, one hundred".