100100020 has 12 divisors (see below), whose sum is σ = 210210084. Its totient is φ = 40040000.

The previous prime is 100099981. The next prime is 100100051. The reversal of 100100020 is 20001001.

It can be written as a sum of positive squares in 2 ways, for example, as 21883684 + 78216336 = 4678^2 + 8844^2 .

It is a Harshad number since it is a multiple of its sum of digits (4).

It is a junction number, because it is equal to n+sod(n) for n = 100099982 and 100100009.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2502481 + ... + 2502520.

It is an arithmetic number, because the mean of its divisors is an integer number (17517507).

Almost surely, 2^100100020 is an apocalyptic number.

100100020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

100100020 is an abundant number, since it is smaller than the sum of its proper divisors (110110064).

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

100100020 is a wasteful number, since it uses less digits than its factorization.

100100020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5005010 (or 5005008 counting only the distinct ones).

The product of its (nonzero) digits is 2, while the sum is 4.

The square root of 100100020 is about 10004.9997501249. Note that the first 3 decimals coincide. The cubic root of 100100020 is about 464.3135823678.

Adding to 100100020 its reverse (20001001), we get a palindrome (120101021).

The spelling of 100100020 in words is "one hundred million, one hundred thousand, twenty".