1287863849 has 4 divisors (see below), whose sum is σ = 1363620564. Its totient is φ = 1212107136.

The previous prime is 1287863809. The next prime is 1287863851. The reversal of 1287863849 is 9483687821.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1052548249 + 235315600 = 32443^2 + 15340^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1287863849 is a prime.

It is a super-2 number, since 2×1287863849² = 3317186587122189602, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1287863794 and 1287863803.

It is not an unprimeable number, because it can be changed into a prime (1287863809) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 37878332 + ... + 37878365.

It is an arithmetic number, because the mean of its divisors is an integer number (340905141).

Almost surely, 2^1287863849 is an apocalyptic number.

It is an amenable number.

1287863849 is a deficient number, since it is larger than the sum of its proper divisors (75756715).

1287863849 is an equidigital number, since it uses as much as digits as its factorization.

1287863849 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75756714.

The product of its digits is 4644864, while the sum is 56.

The square root of 1287863849 is about 35886.8199900744. The cubic root of 1287863849 is about 1087.9860263601.

The spelling of 1287863849 in words is "one billion, two hundred eighty-seven million, eight hundred sixty-three thousand, eight hundred forty-nine".