2661180991 has 8 divisors (see below), whose sum is σ = 3041669120. Its totient is φ = 2280772728.

The previous prime is 2661180979. The next prime is 2661181009. The reversal of 2661180991 is 1990811662.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2661180991 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2661180941) 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, 97630 + ... + 121876.

It is an arithmetic number, because the mean of its divisors is an integer number (380208640).

Almost surely, 2^2661180991 is an apocalyptic number.

2661180991 is a deficient number, since it is larger than the sum of its proper divisors (380488129).

2661180991 is a wasteful number, since it uses less digits than its factorization.

2661180991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39933.

The product of its (nonzero) digits is 46656, while the sum is 43.

The square root of 2661180991 is about 51586.6357790465. The cubic root of 2661180991 is about 1385.7710071539.

The spelling of 2661180991 in words is "two billion, six hundred sixty-one million, one hundred eighty thousand, nine hundred ninety-one".