1555540201 has 4 divisors (see below), whose sum is σ = 1560510292. Its totient is φ = 1550570112.

The previous prime is 1555540187. The next prime is 1555540219. The reversal of 1555540201 is 1020455551.

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 161264601 + 1394275600 = 12699^2 + 37340^2 .

It is a cyclic number.

It is not a de Polignac number, because 1555540201 - 2⁵ = 1555540169 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1555540201.

It is not an unprimeable number, because it can be changed into a prime (1555540501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2484576 + ... + 2485201.

It is an arithmetic number, because the mean of its divisors is an integer number (390127573).

Almost surely, 2^1555540201 is an apocalyptic number.

It is an amenable number.

1555540201 is a deficient number, since it is larger than the sum of its proper divisors (4970091).

1555540201 is an equidigital number, since it uses as much as digits as its factorization.

1555540201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4970090.

The product of its (nonzero) digits is 5000, while the sum is 28.

The square root of 1555540201 is about 39440.3372323311. The cubic root of 1555540201 is about 1158.6717359369.

Adding to 1555540201 its reverse (1020455551), we get a palindrome (2575995752).

The spelling of 1555540201 in words is "one billion, five hundred fifty-five million, five hundred forty thousand, two hundred one".