201643220 has 24 divisors (see below), whose sum is σ = 437111808. Its totient is φ = 78055200.

The previous prime is 201643213. The next prime is 201643249. The reversal of 201643220 is 22346102.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 201643192 and 201643201.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 161996 + ... + 163235.

It is an arithmetic number, because the mean of its divisors is an integer number (18212992).

Almost surely, 2^201643220 is an apocalyptic number.

201643220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

201643220 is an abundant number, since it is smaller than the sum of its proper divisors (235468588).

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

201643220 is a wasteful number, since it uses less digits than its factorization.

201643220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 325271 (or 325269 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 201643220 is about 14200.1133798290. The cubic root of 201643220 is about 586.4007827248.

Adding to 201643220 its reverse (22346102), we get a palindrome (223989322).

The spelling of 201643220 in words is "two hundred one million, six hundred forty-three thousand, two hundred twenty".