20100120 has 128 divisors (see below), whose sum is σ = 65318400. Its totient is φ = 4929536.

The previous prime is 20100097. The next prime is 20100149. The reversal of 20100120 is 2100102.

It is a happy number.

It is a super-3 number, since 3×20100120³ (a number of 23 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (6).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is a junction number, because it is equal to n+sod(n) for n = 20100099 and 20100108.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 120277 + ... + 120443.

It is an arithmetic number, because the mean of its divisors is an integer number (510300).

Almost surely, 2^20100120 is an apocalyptic number.

20100120 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 20100120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32659200).

20100120 is an abundant number, since it is smaller than the sum of its proper divisors (45218280).

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

20100120 is a wasteful number, since it uses less digits than its factorization.

20100120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 257 (or 253 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 6.

The square root of 20100120 is about 4483.3157372641. The cubic root of 20100120 is about 271.8939537585.

Adding to 20100120 its reverse (2100102), we get a palindrome (22200222).

The spelling of 20100120 in words is "twenty million, one hundred thousand, one hundred twenty".