1661318033 has 8 divisors (see below), whose sum is σ = 1674538920. Its totient is φ = 1648113280.

The previous prime is 1661318023. The next prime is 1661318039. The reversal of 1661318033 is 3308131661.

It can be written as a sum of positive squares in 4 ways, for example, as 81414529 + 1579903504 = 9023^2 + 39748^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1661318033 - 2⁶ = 1661317969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1661318039) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 280523 + ... + 286383.

It is an arithmetic number, because the mean of its divisors is an integer number (209317365).

Almost surely, 2^1661318033 is an apocalyptic number.

It is an amenable number.

1661318033 is a deficient number, since it is larger than the sum of its proper divisors (13220887).

1661318033 is a wasteful number, since it uses less digits than its factorization.

1661318033 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8067.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 1661318033 is about 40759.2692893285. The cubic root of 1661318033 is about 1184.3614410517.

Adding to 1661318033 its reverse (3308131661), we get a palindrome (4969449694).

The spelling of 1661318033 in words is "one billion, six hundred sixty-one million, three hundred eighteen thousand, thirty-three".