1861310887 has 2 divisors, whose sum is σ = 1861310888. Its totient is φ = 1861310886.

The previous prime is 1861310861. The next prime is 1861311019. The reversal of 1861310887 is 7880131681.

It is a weak prime.

It is an emirp because it is prime and its reverse (7880131681) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1861310887 - 2¹⁵ = 1861278119 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1861310827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 930655443 + 930655444.

It is an arithmetic number, because the mean of its divisors is an integer number (930655444).

Almost surely, 2^1861310887 is an apocalyptic number.

1861310887 is a deficient number, since it is larger than the sum of its proper divisors (1).

1861310887 is an equidigital number, since it uses as much as digits as its factorization.

1861310887 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64512, while the sum is 43.

The square root of 1861310887 is about 43142.9123611283. The cubic root of 1861310887 is about 1230.0977926962.

The spelling of 1861310887 in words is "one billion, eight hundred sixty-one million, three hundred ten thousand, eight hundred eighty-seven".