201243780 has 36 divisors (see below), whose sum is σ = 610440012. Its totient is φ = 53664960.

The previous prime is 201243743. The next prime is 201243797. The reversal of 201243780 is 87342102.

It can be written as a sum of positive squares in 2 ways, for example, as 119377476 + 81866304 = 10926^2 + 9048^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 558831 + ... + 559190.

It is an arithmetic number, because the mean of its divisors is an integer number (16956667).

Almost surely, 2^201243780 is an apocalyptic number.

201243780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

201243780 is an abundant number, since it is smaller than the sum of its proper divisors (409196232).

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

201243780 is a wasteful number, since it uses less digits than its factorization.

201243780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1118036 (or 1118031 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 201243780 is about 14186.0417312230. The cubic root of 201243780 is about 586.0133215374.

Adding to 201243780 its reverse (87342102), we get a palindrome (288585882).

The spelling of 201243780 in words is "two hundred one million, two hundred forty-three thousand, seven hundred eighty".