20090100 has 72 divisors (see below), whose sum is σ = 58621248. Its totient is φ = 5312000.

The previous prime is 20090099. The next prime is 20090129. The reversal of 20090100 is 109002.

It is a happy number.

It is a super-2 number, since 2×20090100² = 807224236020000, which contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 49900 + ... + 50300.

It is an arithmetic number, because the mean of its divisors is an integer number (814184).

Almost surely, 2^20090100 is an apocalyptic number.

20090100 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 20090100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29310624).

20090100 is an abundant number, since it is smaller than the sum of its proper divisors (38531148).

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

20090100 is a wasteful number, since it uses less digits than its factorization.

20090100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 585 (or 578 counting only the distinct ones).

The product of its (nonzero) digits is 18, while the sum is 12.

The square root of 20090100 is about 4482.1981214578. The cubic root of 20090100 is about 271.8487661304.

Adding to 20090100 its reverse (109002), we get a palindrome (20199102).

The spelling of 20090100 in words is "twenty million, ninety thousand, one hundred".