2661191615 has 4 divisors (see below), whose sum is σ = 3193429944. Its totient is φ = 2128953288.

The previous prime is 2661191591. The next prime is 2661191651. The reversal of 2661191615 is 5161911662.

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

It is a cyclic number.

It is not a de Polignac number, because 2661191615 - 2⁸ = 2661191359 is a prime.

It is a Duffinian number.

It is a congruent 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, 266119157 + ... + 266119166.

It is an arithmetic number, because the mean of its divisors is an integer number (798357486).

Almost surely, 2^2661191615 is an apocalyptic number.

2661191615 is a deficient number, since it is larger than the sum of its proper divisors (532238329).

2661191615 is an equidigital number, since it uses as much as digits as its factorization.

2661191615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 532238328.

The product of its digits is 19440, while the sum is 38.

The square root of 2661191615 is about 51586.7387513497. The cubic root of 2661191615 is about 1385.7728512489.

The spelling of 2661191615 in words is "two billion, six hundred sixty-one million, one hundred ninety-one thousand, six hundred fifteen".