201643520 has 160 divisors (see below), whose sum is σ = 534153312. Its totient is φ = 72548352.

The previous prime is 201643501. The next prime is 201643529. The reversal of 201643520 is 25346102.

It is a tau number, because it is divible by the number of its divisors (160).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201643529) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2429399 + ... + 2429481.

Almost surely, 2^201643520 is an apocalyptic number.

201643520 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 201643520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (267076656).

201643520 is an abundant number, since it is smaller than the sum of its proper divisors (332509792).

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

201643520 is an equidigital number, since it uses as much as digits as its factorization.

201643520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192 (or 176 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 201643520 is about 14200.1239431211. The cubic root of 201643520 is about 586.4010735357.

Adding to 201643520 its reverse (25346102), we get a palindrome (226989622).

The spelling of 201643520 in words is "two hundred one million, six hundred forty-three thousand, five hundred twenty".