205550100 has 324 divisors, whose sum is σ = 771825600. Its totient is φ = 45601920.

The previous prime is 205550099. The next prime is 205550101. The reversal of 205550100 is 1055502.

It is an interprime number because it is at equal distance from previous prime (205550099) and next prime (205550101).

It is a super-2 number, since 2×205550100² = 84501687220020000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205550101) by changing a digit.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 2601861 + ... + 2601939.

Almost surely, 2^205550100 is an apocalyptic number.

205550100 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 205550100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (385912800).

205550100 is an abundant number, since it is smaller than the sum of its proper divisors (566275500).

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

205550100 is a wasteful number, since it uses less digits than its factorization.

205550100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172 (or 155 counting only the distinct ones).

The product of its (nonzero) digits is 250, while the sum is 18.

The square root of 205550100 is about 14337.0185185066. The cubic root of 205550100 is about 590.1637963304.

The spelling of 205550100 in words is "two hundred five million, five hundred fifty thousand, one hundred".