1816531201 has 4 divisors (see below), whose sum is σ = 1826679600. Its totient is φ = 1806382804.

The previous prime is 1816531187. The next prime is 1816531217. The reversal of 1816531201 is 1021356181.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1021356181 = 6121 ⋅166861.

It is a cyclic number.

It is not a de Polignac number, because 1816531201 - 2⁹ = 1816530689 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 1816531201.

It is not an unprimeable number, because it can be changed into a prime (1816541201) 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, 5073931 + ... + 5074288.

It is an arithmetic number, because the mean of its divisors is an integer number (456669900).

Almost surely, 2^1816531201 is an apocalyptic number.

It is an amenable number.

1816531201 is a deficient number, since it is larger than the sum of its proper divisors (10148399).

1816531201 is a wasteful number, since it uses less digits than its factorization.

1816531201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10148398.

The product of its (nonzero) digits is 1440, while the sum is 28.

The square root of 1816531201 is about 42620.7836741654. The cubic root of 1816531201 is about 1220.1529865033.

Adding to 1816531201 its reverse (1021356181), we get a palindrome (2837887382).

The spelling of 1816531201 in words is "one billion, eight hundred sixteen million, five hundred thirty-one thousand, two hundred one".