1665122001 has 16 divisors (see below), whose sum is σ = 2355937344. Its totient is φ = 1042481664.

The previous prime is 1665121951. The next prime is 1665122021. The reversal of 1665122001 is 1002215661.

It is not a de Polignac number, because 1665122001 - 2⁷ = 1665121873 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1665122021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12415 + ... + 59028.

It is an arithmetic number, because the mean of its divisors is an integer number (147246084).

Almost surely, 2^1665122001 is an apocalyptic number.

It is an amenable number.

1665122001 is a deficient number, since it is larger than the sum of its proper divisors (690815343).

1665122001 is a wasteful number, since it uses less digits than its factorization.

1665122001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71920.

The product of its (nonzero) digits is 720, while the sum is 24.

The square root of 1665122001 is about 40805.9064474740. The cubic root of 1665122001 is about 1185.2647075510.

Adding to 1665122001 its reverse (1002215661), we get a palindrome (2667337662).

The spelling of 1665122001 in words is "one billion, six hundred sixty-five million, one hundred twenty-two thousand, one".