2778881 has 4 divisors (see below), whose sum is σ = 3175872. Its totient is φ = 2381892.

The previous prime is 2778877. The next prime is 2778901. The reversal of 2778881 is 1888772.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2778881 - 2² = 2778877 is a prime.

It is a super-2 number, since 2×2778881² = 15444359224322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (2778851) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 198485 + ... + 198498.

It is an arithmetic number, because the mean of its divisors is an integer number (793968).

2^2778881 is an apocalyptic number.

It is an amenable number.

2778881 is a deficient number, since it is larger than the sum of its proper divisors (396991).

2778881 is an equidigital number, since it uses as much as digits as its factorization.

2778881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 396990.

The product of its digits is 50176, while the sum is 41.

The square root of 2778881 is about 1666.9976004782. The cubic root of 2778881 is about 140.5907182937.

The spelling of 2778881 in words is "two million, seven hundred seventy-eight thousand, eight hundred eighty-one".