1287775249 has 4 divisors (see below), whose sum is σ = 1288590336. Its totient is φ = 1286960164.

The previous prime is 1287775199. The next prime is 1287775253. The reversal of 1287775249 is 9425777821.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1287775249 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1287775196 and 1287775205.

It is not an unprimeable number, because it can be changed into a prime (1287775549) 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, 405169 + ... + 408334.

It is an arithmetic number, because the mean of its divisors is an integer number (322147584).

Almost surely, 2^1287775249 is an apocalyptic number.

It is an amenable number.

1287775249 is a deficient number, since it is larger than the sum of its proper divisors (815087).

1287775249 is an equidigital number, since it uses as much as digits as its factorization.

1287775249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 815086.

The product of its digits is 1975680, while the sum is 52.

The square root of 1287775249 is about 35885.5855323555. The cubic root of 1287775249 is about 1087.9610760589.

The spelling of 1287775249 in words is "one billion, two hundred eighty-seven million, seven hundred seventy-five thousand, two hundred forty-nine".