2778621 has 8 divisors (see below), whose sum is σ = 3724800. Its totient is φ = 1842432.

The previous prime is 2778619. The next prime is 2778647. The reversal of 2778621 is 1268772.

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

It is not a de Polignac number, because 2778621 - 2¹ = 2778619 is a prime.

2778621 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2778121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1821 + ... + 2978.

It is an arithmetic number, because the mean of its divisors is an integer number (465600).

2^2778621 is an apocalyptic number.

It is an amenable number.

2778621 is a deficient number, since it is larger than the sum of its proper divisors (946179).

2778621 is a wasteful number, since it uses less digits than its factorization.

2778621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4995.

The product of its digits is 9408, while the sum is 33.

The square root of 2778621 is about 1666.9196141386. The cubic root of 2778621 is about 140.5863334679.

The spelling of 2778621 in words is "two million, seven hundred seventy-eight thousand, six hundred twenty-one".