2191132778 has 8 divisors (see below), whose sum is σ = 3312579072. Its totient is φ = 1086939756.

The previous prime is 2191132759. The next prime is 2191132781. The reversal of 2191132778 is 8772311912.

It is a happy number.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4313000 + ... + 4313507.

It is an arithmetic number, because the mean of its divisors is an integer number (414072384).

Almost surely, 2^2191132778 is an apocalyptic number.

2191132778 is a deficient number, since it is larger than the sum of its proper divisors (1121446294).

2191132778 is a wasteful number, since it uses less digits than its factorization.

2191132778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8626636.

The product of its digits is 42336, while the sum is 41.

The square root of 2191132778 is about 46809.5372547091. The cubic root of 2191132778 is about 1298.8417253083.

The spelling of 2191132778 in words is "two billion, one hundred ninety-one million, one hundred thirty-two thousand, seven hundred seventy-eight".