1287639166 has 24 divisors (see below), whose sum is σ = 2168197920. Its totient is φ = 572832480.

The previous prime is 1287639163. The next prime is 1287639169. The reversal of 1287639166 is 6619367821.

It is an interprime number because it is at equal distance from previous prime (1287639163) and next prime (1287639169).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1287639163) 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 11 ways as a sum of consecutive naturals, for example, 45231 + ... + 67978.

It is an arithmetic number, because the mean of its divisors is an integer number (90341580).

Almost surely, 2^1287639166 is an apocalyptic number.

1287639166 is a deficient number, since it is larger than the sum of its proper divisors (880558754).

1287639166 is a wasteful number, since it uses less digits than its factorization.

1287639166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113280 (or 113269 counting only the distinct ones).

The product of its digits is 653184, while the sum is 49.

The square root of 1287639166 is about 35883.6894145516. The cubic root of 1287639166 is about 1087.9227520262.

The spelling of 1287639166 in words is "one billion, two hundred eighty-seven million, six hundred thirty-nine thousand, one hundred sixty-six".