2779815420 has 144 divisors (see below), whose sum is σ = 8841111552. Its totient is φ = 705640320.

The previous prime is 2779815413. The next prime is 2779815433. The reversal of 2779815420 is 245189772.

It is a happy number.

2779815420 is a `hidden beast` number, since 27 + 7 + 9 + 81 + 542 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 921715 + ... + 924725.

It is an arithmetic number, because the mean of its divisors is an integer number (61396608).

Almost surely, 2^2779815420 is an apocalyptic number.

2779815420 is a gapful number since it is divisible by the number (20) 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 2779815420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4420555776).

2779815420 is an abundant number, since it is smaller than the sum of its proper divisors (6061296132).

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

2779815420 is a wasteful number, since it uses less digits than its factorization.

2779815420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3272 (or 3267 counting only the distinct ones).

The product of its (nonzero) digits is 282240, while the sum is 45.

The square root of 2779815420 is about 52723.9548971812. The cubic root of 2779815420 is about 1406.0647476265.

The spelling of 2779815420 in words is "two billion, seven hundred seventy-nine million, eight hundred fifteen thousand, four hundred twenty".