1287767940 has 144 divisors (see below), whose sum is σ = 3865417920. Its totient is φ = 319438080.

The previous prime is 1287767927. The next prime is 1287767941. The reversal of 1287767940 is 497677821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1287767941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7114650 + ... + 7114830.

It is an arithmetic number, because the mean of its divisors is an integer number (26843180).

Almost surely, 2^1287767940 is an apocalyptic number.

1287767940 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1287767940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1932708960).

1287767940 is an abundant number, since it is smaller than the sum of its proper divisors (2577649980).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1287767940 is a wasteful number, since it uses less digits than its factorization.

1287767940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 370 (or 289 counting only the distinct ones).

The product of its (nonzero) digits is 1185408, while the sum is 51.

The square root of 1287767940 is about 35885.4836946641. The cubic root of 1287767940 is about 1087.9590177488.

The spelling of 1287767940 in words is "one billion, two hundred eighty-seven million, seven hundred sixty-seven thousand, nine hundred forty".