1287399616 has 14 divisors (see below), whose sum is σ = 2554683740. Its totient is φ = 643699776.

The previous prime is 1287399601. The next prime is 1287399623. The reversal of 1287399616 is 6169937821.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10057746 + ... + 10057873.

It is an arithmetic number, because the mean of its divisors is an integer number (182477410).

Almost surely, 2^1287399616 is an apocalyptic number.

1287399616 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1287399616 is a deficient number, since it is larger than the sum of its proper divisors (1267284124).

1287399616 is an equidigital number, since it uses as much as digits as its factorization.

1287399616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20115631 (or 20115621 counting only the distinct ones).

The product of its digits is 979776, while the sum is 52.

The square root of 1287399616 is about 35880.3513918133. The cubic root of 1287399616 is about 1087.8552827990.

The spelling of 1287399616 in words is "one billion, two hundred eighty-seven million, three hundred ninety-nine thousand, six hundred sixteen".