661165079 has 4 divisors (see below), whose sum is σ = 661226280. Its totient is φ = 661103880.

The previous prime is 661165073. The next prime is 661165081. The reversal of 661165079 is 970561166.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 970561166 = 2 ⋅485280583.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-661165079 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661165073) 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, 9584 + ... + 37605.

It is an arithmetic number, because the mean of its divisors is an integer number (165306570).

Almost surely, 2^661165079 is an apocalyptic number.

661165079 is a deficient number, since it is larger than the sum of its proper divisors (61201).

661165079 is a wasteful number, since it uses less digits than its factorization.

661165079 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61200.

The product of its (nonzero) digits is 68040, while the sum is 41.

The square root of 661165079 is about 25713.1304784151. The cubic root of 661165079 is about 871.1707842405.

The spelling of 661165079 in words is "six hundred sixty-one million, one hundred sixty-five thousand, seventy-nine".