1868188397 has 2 divisors, whose sum is σ = 1868188398. Its totient is φ = 1868188396.

The previous prime is 1868188393. The next prime is 1868188447. The reversal of 1868188397 is 7938818681.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1857092836 + 11095561 = 43094^2 + 3331^2 .

It is an emirp because it is prime and its reverse (7938818681) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1868188397 - 2² = 1868188393 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1868188393) 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, 934094198 + 934094199.

It is an arithmetic number, because the mean of its divisors is an integer number (934094199).

Almost surely, 2^1868188397 is an apocalyptic number.

It is an amenable number.

1868188397 is a deficient number, since it is larger than the sum of its proper divisors (1).

1868188397 is an equidigital number, since it uses as much as digits as its factorization.

1868188397 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4644864, while the sum is 59.

The square root of 1868188397 is about 43222.5450083634. The cubic root of 1868188397 is about 1231.6109934919.

The spelling of 1868188397 in words is "one billion, eight hundred sixty-eight million, one hundred eighty-eight thousand, three hundred ninety-seven".