665461121 has 8 divisors (see below), whose sum is σ = 716853480. Its totient is φ = 614097792.

The previous prime is 665461117. The next prime is 665461129. The reversal of 665461121 is 121164566.

It can be written as a sum of positive squares in 4 ways, for example, as 41460721 + 624000400 = 6439^2 + 24980^2 .

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 665461121 - 2² = 665461117 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665461129) 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, 74735 + ... + 83163.

It is an arithmetic number, because the mean of its divisors is an integer number (89606685).

Almost surely, 2^665461121 is an apocalyptic number.

It is an amenable number.

665461121 is a deficient number, since it is larger than the sum of its proper divisors (51392359).

665461121 is a wasteful number, since it uses less digits than its factorization.

665461121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14515.

The product of its digits is 8640, while the sum is 32.

The square root of 665461121 is about 25796.5331197818. The cubic root of 665461121 is about 873.0535764427.

The spelling of 665461121 in words is "six hundred sixty-five million, four hundred sixty-one thousand, one hundred twenty-one".