2778516 has 48 divisors (see below), whose sum is σ = 7761600. Its totient is φ = 854496.

The previous prime is 2778481. The next prime is 2778521. The reversal of 2778516 is 6158772.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a d-powerful number, because it can be written as 2⁵ + 7 + 7⁷ + 8³ + 5⁹ + 1 + 6⁴ .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 415 + ... + 2393.

It is an arithmetic number, because the mean of its divisors is an integer number (161700).

2^2778516 is an apocalyptic number.

2778516 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2778516, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3880800).

2778516 is an abundant number, since it is smaller than the sum of its proper divisors (4983084).

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

2778516 is a wasteful number, since it uses less digits than its factorization.

2778516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2005 (or 1997 counting only the distinct ones).

The product of its digits is 23520, while the sum is 36.

The square root of 2778516 is about 1666.8881186210. Note that the first 3 decimals coincide. The cubic root of 2778516 is about 140.5845625954.

The spelling of 2778516 in words is "two million, seven hundred seventy-eight thousand, five hundred sixteen".