2778933891 has 16 divisors (see below), whose sum is σ = 3823110144. Its totient is φ = 1794503424.

The previous prime is 2778933889. The next prime is 2778933907. The reversal of 2778933891 is 1983398772.

It is not a de Polignac number, because 2778933891 - 2¹ = 2778933889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2778933841) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 87915 + ... + 115268.

It is an arithmetic number, because the mean of its divisors is an integer number (238944384).

Almost surely, 2^2778933891 is an apocalyptic number.

2778933891 is a deficient number, since it is larger than the sum of its proper divisors (1044176253).

2778933891 is a wasteful number, since it uses less digits than its factorization.

2778933891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203330.

The product of its digits is 4572288, while the sum is 57.

The square root of 2778933891 is about 52715.5943815490. The cubic root of 2778933891 is about 1405.9161025179.

The spelling of 2778933891 in words is "two billion, seven hundred seventy-eight million, nine hundred thirty-three thousand, eight hundred ninety-one".