660405001 has 4 divisors (see below), whose sum is σ = 699252372. Its totient is φ = 621557632.

The previous prime is 660404989. The next prime is 660405029. The reversal of 660405001 is 100504066.

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 607129600 + 53275401 = 24640^2 + 7299^2 .

It is a cyclic number.

It is not a de Polignac number, because 660405001 - 2¹⁵ = 660372233 is a prime.

It is a super-2 number, since 2×660405001² = 872269530691620002, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (660405041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19423660 + ... + 19423693.

It is an arithmetic number, because the mean of its divisors is an integer number (174813093).

Almost surely, 2^660405001 is an apocalyptic number.

It is an amenable number.

660405001 is a deficient number, since it is larger than the sum of its proper divisors (38847371).

660405001 is a wasteful number, since it uses less digits than its factorization.

660405001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38847370.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 660405001 is about 25698.3462697505. The cubic root of 660405001 is about 870.8368224356.

Adding to 660405001 its reverse (100504066), we get a palindrome (760909067).

The spelling of 660405001 in words is "six hundred sixty million, four hundred five thousand, one".