201520645 has 4 divisors (see below), whose sum is σ = 241824780. Its totient is φ = 161216512.

The previous prime is 201520609. The next prime is 201520663. The reversal of 201520645 is 546025102.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 96314596 + 105206049 = 9814^2 + 10257^2 .

It is a cyclic number.

It is not a de Polignac number, because 201520645 - 2⁹ = 201520133 is a prime.

It is a super-2 number, since 2×201520645² = 81221140722432050, which contains 22 as substring.

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 3 ways as a sum of consecutive naturals, for example, 20152060 + ... + 20152069.

It is an arithmetic number, because the mean of its divisors is an integer number (60456195).

Almost surely, 2^201520645 is an apocalyptic number.

It is an amenable number.

201520645 is a deficient number, since it is larger than the sum of its proper divisors (40304135).

201520645 is an equidigital number, since it uses as much as digits as its factorization.

201520645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40304134.

The product of its (nonzero) digits is 2400, while the sum is 25.

The square root of 201520645 is about 14195.7967370627. The cubic root of 201520645 is about 586.2819380888.

Adding to 201520645 its reverse (546025102), we get a palindrome (747545747).

The spelling of 201520645 in words is "two hundred one million, five hundred twenty thousand, six hundred forty-five".