1863987897 has 4 divisors (see below), whose sum is σ = 2485317200. Its totient is φ = 1242658596.

The previous prime is 1863987893. The next prime is 1863987911. The reversal of 1863987897 is 7987893681.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1863987897 - 2² = 1863987893 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1863987893) 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 3 ways as a sum of consecutive naturals, for example, 310664647 + ... + 310664652.

It is an arithmetic number, because the mean of its divisors is an integer number (621329300).

Almost surely, 2^1863987897 is an apocalyptic number.

It is an amenable number.

1863987897 is a deficient number, since it is larger than the sum of its proper divisors (621329303).

1863987897 is an equidigital number, since it uses as much as digits as its factorization.

1863987897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 621329302.

The product of its digits is 36578304, while the sum is 66.

The square root of 1863987897 is about 43173.9261244562. The cubic root of 1863987897 is about 1230.6872350932.

The spelling of 1863987897 in words is "one billion, eight hundred sixty-three million, nine hundred eighty-seven thousand, eight hundred ninety-seven".