1878563861 has 2 divisors, whose sum is σ = 1878563862. Its totient is φ = 1878563860.

The previous prime is 1878563837. The next prime is 1878563881. The reversal of 1878563861 is 1683658781.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1214522500 + 664041361 = 34850^2 + 25769^2 .

It is a cyclic number.

It is not a de Polignac number, because 1878563861 - 2³⁰ = 804822037 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1878563881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 939281930 + 939281931.

It is an arithmetic number, because the mean of its divisors is an integer number (939281931).

Almost surely, 2^1878563861 is an apocalyptic number.

It is an amenable number.

1878563861 is a deficient number, since it is larger than the sum of its proper divisors (1).

1878563861 is an equidigital number, since it uses as much as digits as its factorization.

1878563861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1935360, while the sum is 53.

The square root of 1878563861 is about 43342.4025753072. The cubic root of 1878563861 is about 1233.8868082105.

The spelling of 1878563861 in words is "one billion, eight hundred seventy-eight million, five hundred sixty-three thousand, eight hundred sixty-one".