20121600 has 144 divisors (see below), whose sum is σ = 67026960. Its totient is φ = 5324800.

The previous prime is 20121581. The next prime is 20121623. The reversal of 20121600 is 612102.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 153535 + ... + 153665.

It is an arithmetic number, because the mean of its divisors is an integer number (465465).

Almost surely, 2^20121600 is an apocalyptic number.

20121600 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 20121600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33513480).

20121600 is an abundant number, since it is smaller than the sum of its proper divisors (46905360).

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

20121600 is a wasteful number, since it uses less digits than its factorization.

20121600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166 (or 141 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 20121600 is about 4485.7106460404. The cubic root of 20121600 is about 271.9907724667.

Adding to 20121600 its reverse (612102), we get a palindrome (20733702).

The spelling of 20121600 in words is "twenty million, one hundred twenty-one thousand, six hundred".