20121100 has 18 divisors (see below), whose sum is σ = 43663004. Its totient is φ = 8048400.

The previous prime is 20121097. The next prime is 20121103. The reversal of 20121100 is 112102.

It is an interprime number because it is at equal distance from previous prime (20121097) and next prime (20121103).

It is not an unprimeable number, because it can be changed into a prime (20121103) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 100506 + ... + 100705.

Almost surely, 2^20121100 is an apocalyptic number.

20121100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20121100 is an abundant number, since it is smaller than the sum of its proper divisors (23541904).

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

20121100 is a wasteful number, since it uses less digits than its factorization.

20121100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 201225 (or 201218 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 7.

The square root of 20121100 is about 4485.6549131649. The cubic root of 20121100 is about 271.9885195558.

Adding to 20121100 its reverse (112102), we get a palindrome (20233202).

The spelling of 20121100 in words is "twenty million, one hundred twenty-one thousand, one hundred".