2661195709 has 4 divisors (see below), whose sum is σ = 2662165116. Its totient is φ = 2660226304.

The previous prime is 2661195707. The next prime is 2661195731. The reversal of 2661195709 is 9075911662.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2362251609 + 298944100 = 48603^2 + 17290^2 .

It is a cyclic number.

It is not a de Polignac number, because 2661195709 - 2¹ = 2661195707 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 (2661195707) 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, 480574 + ... + 486079.

It is an arithmetic number, because the mean of its divisors is an integer number (665541279).

Almost surely, 2^2661195709 is an apocalyptic number.

It is an amenable number.

2661195709 is a deficient number, since it is larger than the sum of its proper divisors (969407).

2661195709 is an equidigital number, since it uses as much as digits as its factorization.

2661195709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 969406.

The product of its (nonzero) digits is 204120, while the sum is 46.

The square root of 2661195709 is about 51586.7784320750. The cubic root of 2661195709 is about 1385.7735618768.

The spelling of 2661195709 in words is "two billion, six hundred sixty-one million, one hundred ninety-five thousand, seven hundred nine".