1287121763 has 4 divisors (see below), whose sum is σ = 1289938680. Its totient is φ = 1284304848.

The previous prime is 1287121729. The next prime is 1287121783. The reversal of 1287121763 is 3671217821.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1287121763 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1287121783) 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 in 3 ways as a sum of consecutive naturals, for example, 1407773 + ... + 1408686.

It is an arithmetic number, because the mean of its divisors is an integer number (322484670).

Almost surely, 2^1287121763 is an apocalyptic number.

1287121763 is a deficient number, since it is larger than the sum of its proper divisors (2816917).

1287121763 is an equidigital number, since it uses as much as digits as its factorization.

1287121763 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2816916.

The product of its digits is 28224, while the sum is 38.

The square root of 1287121763 is about 35876.4792447642. The cubic root of 1287121763 is about 1087.7770150521. Note that the first 3 decimals are identical.

The spelling of 1287121763 in words is "one billion, two hundred eighty-seven million, one hundred twenty-one thousand, seven hundred sixty-three".