2878725821 has 6 divisors (see below), whose sum is σ = 3058023930. Its totient is φ = 2709388736.

The previous prime is 2878725809. The next prime is 2878725823. The reversal of 2878725821 is 1285278782.

It can be written as a sum of positive squares in 3 ways, for example, as 1878268921 + 1000456900 = 43339^2 + 31630^2 .

It is not a de Polignac number, because 2878725821 - 2⁶ = 2878725757 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2878725821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2878725823) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4980206 + ... + 4980783.

It is an arithmetic number, because the mean of its divisors is an integer number (509670655).

Almost surely, 2^2878725821 is an apocalyptic number.

It is an amenable number.

2878725821 is a deficient number, since it is larger than the sum of its proper divisors (179298109).

2878725821 is an equidigital number, since it uses as much as digits as its factorization.

2878725821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9961023 (or 9961006 counting only the distinct ones).

The product of its digits is 1003520, while the sum is 50.

The square root of 2878725821 is about 53653.7586847371. The cubic root of 2878725821 is about 1422.5474705326.

The spelling of 2878725821 in words is "two billion, eight hundred seventy-eight million, seven hundred twenty-five thousand, eight hundred twenty-one".