1861878125 has 12 divisors (see below), whose sum is σ = 2327202612. Its totient is φ = 1489500000.

The previous prime is 1861878103. The next prime is 1861878127. The reversal of 1861878125 is 5218781681.

It can be written as a sum of positive squares in 6 ways, for example, as 1755107236 + 106770889 = 41894^2 + 10333^2 .

It is not a de Polignac number, because 1861878125 - 2⁸ = 1861877869 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1861878125.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1861878127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 294776 + ... + 301025.

It is an arithmetic number, because the mean of its divisors is an integer number (193933551).

Almost surely, 2^1861878125 is an apocalyptic number.

It is an amenable number.

1861878125 is a deficient number, since it is larger than the sum of its proper divisors (465324487).

1861878125 is an frugal number, since it uses more digits than its factorization.

1861878125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 595826 (or 595806 counting only the distinct ones).

The product of its digits is 215040, while the sum is 47.

The square root of 1861878125 is about 43149.4858022665. The cubic root of 1861878125 is about 1230.2227382113. Note that the first 3 decimals are identical.

The spelling of 1861878125 in words is "one billion, eight hundred sixty-one million, eight hundred seventy-eight thousand, one hundred twenty-five".