1868633861 has 2 divisors, whose sum is σ = 1868633862. Its totient is φ = 1868633860.

The previous prime is 1868633783. The next prime is 1868633891. The reversal of 1868633861 is 1683368681.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1003685761 + 864948100 = 31681^2 + 29410^2 .

It is a cyclic number.

It is not a de Polignac number, because 1868633861 - 2²⁶ = 1801524997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1868633891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 934316930 + 934316931.

It is an arithmetic number, because the mean of its divisors is an integer number (934316931).

Almost surely, 2^1868633861 is an apocalyptic number.

It is an amenable number.

1868633861 is a deficient number, since it is larger than the sum of its proper divisors (1).

1868633861 is an equidigital number, since it uses as much as digits as its factorization.

1868633861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 995328, while the sum is 50.

The square root of 1868633861 is about 43227.6978452473. The cubic root of 1868633861 is about 1231.7088770457.

The spelling of 1868633861 in words is "one billion, eight hundred sixty-eight million, six hundred thirty-three thousand, eight hundred sixty-one".