661084265 has 4 divisors (see below), whose sum is σ = 793301124. Its totient is φ = 528867408.

The previous prime is 661084241. The next prime is 661084273. The reversal of 661084265 is 562480166.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 562480166 = 2 ⋅281240083.

It can be written as a sum of positive squares in 2 ways, for example, as 263640169 + 397444096 = 16237^2 + 19936^2 .

It is a cyclic number.

It is not a de Polignac number, because 661084265 - 2⁶ = 661084201 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66108422 + ... + 66108431.

It is an arithmetic number, because the mean of its divisors is an integer number (198325281).

Almost surely, 2^661084265 is an apocalyptic number.

It is an amenable number.

661084265 is a deficient number, since it is larger than the sum of its proper divisors (132216859).

661084265 is a wasteful number, since it uses less digits than its factorization.

661084265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132216858.

The product of its (nonzero) digits is 69120, while the sum is 38.

The square root of 661084265 is about 25711.5589764604. The cubic root of 661084265 is about 871.1352884838.

The spelling of 661084265 in words is "six hundred sixty-one million, eighty-four thousand, two hundred sixty-five".