1665274001 has 4 divisors (see below), whose sum is σ = 1665612912. Its totient is φ = 1664935092.

The previous prime is 1665273979. The next prime is 1665274007. The reversal of 1665274001 is 1004725661.

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: 1004725661 = 347 ⋅2895463.

It is a cyclic number.

It is not a de Polignac number, because 1665274001 - 2⁶ = 1665273937 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1665274007) 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, 161975 + ... + 171948.

It is an arithmetic number, because the mean of its divisors is an integer number (416403228).

Almost surely, 2^1665274001 is an apocalyptic number.

It is an amenable number.

1665274001 is a deficient number, since it is larger than the sum of its proper divisors (338911).

1665274001 is an equidigital number, since it uses as much as digits as its factorization.

1665274001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 338910.

The product of its (nonzero) digits is 10080, while the sum is 32.

The square root of 1665274001 is about 40807.7688804473. The cubic root of 1665274001 is about 1185.3007719262.

Adding to 1665274001 its reverse (1004725661), we get a palindrome (2669999662).

The spelling of 1665274001 in words is "one billion, six hundred sixty-five million, two hundred seventy-four thousand, one".