1287321617 has 16 divisors (see below), whose sum is σ = 1385112960. Its totient is φ = 1192104192.

The previous prime is 1287321589. The next prime is 1287321619. The reversal of 1287321617 is 7161237821.

It is not a de Polignac number, because 1287321617 - 2²⁶ = 1220212753 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1287321619) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 369359 + ... + 372827.

It is an arithmetic number, because the mean of its divisors is an integer number (86569560).

Almost surely, 2^1287321617 is an apocalyptic number.

1287321617 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

1287321617 is a deficient number, since it is larger than the sum of its proper divisors (97791343).

1287321617 is a wasteful number, since it uses less digits than its factorization.

1287321617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3832.

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

The square root of 1287321617 is about 35879.2644434080. The cubic root of 1287321617 is about 1087.8333125843.

The spelling of 1287321617 in words is "one billion, two hundred eighty-seven million, three hundred twenty-one thousand, six hundred seventeen".