2778987 has 8 divisors (see below), whose sum is σ = 3728704. Its totient is φ = 1840968.

The previous prime is 2778967. The next prime is 2778989. The reversal of 2778987 is 7898772.

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

It is a de Polignac number, because none of the positive numbers 2^k-2778987 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2778989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2353 + ... + 3330.

It is an arithmetic number, because the mean of its divisors is an integer number (466088).

2^2778987 is an apocalyptic number.

2778987 is a deficient number, since it is larger than the sum of its proper divisors (949717).

2778987 is a wasteful number, since it uses less digits than its factorization.

2778987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5849.

The product of its digits is 395136, while the sum is 48.

The square root of 2778987 is about 1667.0293938620. The cubic root of 2778987 is about 140.5925058749.

The spelling of 2778987 in words is "two million, seven hundred seventy-eight thousand, nine hundred eighty-seven".