1287478817 has 4 divisors (see below), whose sum is σ = 1355240880. Its totient is φ = 1219716756.

The previous prime is 1287478811. The next prime is 1287478831. The reversal of 1287478817 is 7188747821.

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 not a de Polignac number, because 1287478817 - 2³⁰ = 213736993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1287478811) 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, 33881003 + ... + 33881040.

It is an arithmetic number, because the mean of its divisors is an integer number (338810220).

Almost surely, 2^1287478817 is an apocalyptic number.

It is an amenable number.

1287478817 is a deficient number, since it is larger than the sum of its proper divisors (67762063).

1287478817 is an equidigital number, since it uses as much as digits as its factorization.

1287478817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67762062.

The product of its digits is 1404928, while the sum is 53.

The square root of 1287478817 is about 35881.4550568953. The cubic root of 1287478817 is about 1087.8775906767.

The spelling of 1287478817 in words is "one billion, two hundred eighty-seven million, four hundred seventy-eight thousand, eight hundred seventeen".