20280100 has 36 divisors (see below), whose sum is σ = 44354800. Its totient is φ = 8048160.

The previous prime is 20280067. The next prime is 20280101. The reversal of 20280100 is 108202.

It is a super-2 number, since 2×20280100² = 822564912020000, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20280101) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13171 + ... + 14629.

Almost surely, 2^20280100 is an apocalyptic number.

20280100 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 20280100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22177400).

20280100 is an abundant number, since it is smaller than the sum of its proper divisors (24074700).

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

20280100 is a wasteful number, since it uses less digits than its factorization.

20280100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1612 (or 1605 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 20280100 is about 4503.3432025552. The cubic root of 20280100 is about 272.7030722634.

Adding to 20280100 its reverse (108202), we get a palindrome (20388302).

The spelling of 20280100 in words is "twenty million, two hundred eighty thousand, one hundred".