1287901917 has 16 divisors (see below), whose sum is σ = 1909994880. Its totient is φ = 857704896.

The previous prime is 1287901903. The next prime is 1287901921. The reversal of 1287901917 is 7191097821.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-1287901917 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1287901117) 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 15 ways as a sum of consecutive naturals, for example, 1968 + ... + 50790.

It is an arithmetic number, because the mean of its divisors is an integer number (119374680).

Almost surely, 2^1287901917 is an apocalyptic number.

It is an amenable number.

1287901917 is a deficient number, since it is larger than the sum of its proper divisors (622092963).

1287901917 is an equidigital number, since it uses as much as digits as its factorization.

1287901917 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49809 (or 49803 counting only the distinct ones).

The product of its (nonzero) digits is 63504, while the sum is 45.

The square root of 1287901917 is about 35887.3503758636. The cubic root of 1287901917 is about 1087.9967461899.

The spelling of 1287901917 in words is "one billion, two hundred eighty-seven million, nine hundred one thousand, nine hundred seventeen".