2778649920 has 140 divisors (see below), whose sum is σ = 9884238804. Its totient is φ = 740966400.

The previous prime is 2778649919. The next prime is 2778649931. The reversal of 2778649920 is 299468772.

2778649920 is a `hidden beast` number, since 2 + 77 + 86 + 499 + 2 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 534164544 + 2244485376 = 23112^2 + 47376^2 .

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 27681 + ... + 79520.

Almost surely, 2^2778649920 is an apocalyptic number.

2778649920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2778649920 is an abundant number, since it is smaller than the sum of its proper divisors (7105588884).

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

2778649920 is a wasteful number, since it uses less digits than its factorization.

2778649920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107230 (or 107211 counting only the distinct ones).

The product of its (nonzero) digits is 3048192, while the sum is 54.

The square root of 2778649920 is about 52712.9008877334. The cubic root of 2778649920 is about 1405.8682120897.

The spelling of 2778649920 in words is "two billion, seven hundred seventy-eight million, six hundred forty-nine thousand, nine hundred twenty".