1878878261 has 4 divisors (see below), whose sum is σ = 2023407372. Its totient is φ = 1734349152.

The previous prime is 1878878237. The next prime is 1878878279. The reversal of 1878878261 is 1628788781.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1628788781 = 2237 ⋅728113.

It can be written as a sum of positive squares in 2 ways, for example, as 757900900 + 1120977361 = 27530^2 + 33481^2 .

It is a cyclic number.

It is not a de Polignac number, because 1878878261 - 2¹⁰ = 1878877237 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1878878197 and 1878878206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1878878231) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 72264536 + ... + 72264561.

It is an arithmetic number, because the mean of its divisors is an integer number (505851843).

Almost surely, 2^1878878261 is an apocalyptic number.

It is an amenable number.

1878878261 is a deficient number, since it is larger than the sum of its proper divisors (144529111).

1878878261 is a wasteful number, since it uses less digits than its factorization.

1878878261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144529110.

The product of its digits is 2408448, while the sum is 56.

The square root of 1878878261 is about 43346.0293567935. The cubic root of 1878878261 is about 1233.9556395805.

The spelling of 1878878261 in words is "one billion, eight hundred seventy-eight million, eight hundred seventy-eight thousand, two hundred sixty-one".