665235101 has 4 divisors (see below), whose sum is σ = 665790204. Its totient is φ = 664680000.

The previous prime is 665235059. The next prime is 665235119. The reversal of 665235101 is 101532566.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 101532566 = 2 ⋅50766283.

It can be written as a sum of positive squares in 2 ways, for example, as 132825625 + 532409476 = 11525^2 + 23074^2 .

It is a cyclic number.

It is not a de Polignac number, because 665235101 - 2¹⁰ = 665234077 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665235121) 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, 275750 + ... + 278151.

It is an arithmetic number, because the mean of its divisors is an integer number (166447551).

Almost surely, 2^665235101 is an apocalyptic number.

It is an amenable number.

665235101 is a deficient number, since it is larger than the sum of its proper divisors (555103).

665235101 is a wasteful number, since it uses less digits than its factorization.

665235101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 555102.

The product of its (nonzero) digits is 5400, while the sum is 29.

The square root of 665235101 is about 25792.1519265066. The cubic root of 665235101 is about 872.9547227268.

Adding to 665235101 its reverse (101532566), we get a palindrome (766767667).

The spelling of 665235101 in words is "six hundred sixty-five million, two hundred thirty-five thousand, one hundred one".