2191420278 has 16 divisors (see below), whose sum is σ = 4869822960. Its totient is φ = 730473408.

The previous prime is 2191420277. The next prime is 2191420291. The reversal of 2191420278 is 8720241912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2191420277) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20290875 + ... + 20290982.

It is an arithmetic number, because the mean of its divisors is an integer number (304363935).

Almost surely, 2^2191420278 is an apocalyptic number.

2191420278 is an abundant number, since it is smaller than the sum of its proper divisors (2678402682).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2191420278 is a wasteful number, since it uses less digits than its factorization.

2191420278 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40581868 (or 40581862 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The square root of 2191420278 is about 46812.6081093545. The cubic root of 2191420278 is about 1298.8985301216.

The spelling of 2191420278 in words is "two billion, one hundred ninety-one million, four hundred twenty thousand, two hundred seventy-eight".