1287977864 has 8 divisors (see below), whose sum is σ = 2414958510. Its totient is φ = 643988928.

The previous prime is 1287977861. The next prime is 1287977879. The reversal of 1287977864 is 4687797821.

It can be written as a sum of positive squares in only one way, i.e., 1078596964 + 209380900 = 32842^2 + 14470^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (1287977861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80498609 + ... + 80498624.

Almost surely, 2^1287977864 is an apocalyptic number.

It is an amenable number.

1287977864 is a deficient number, since it is larger than the sum of its proper divisors (1126980646).

1287977864 is a wasteful number, since it uses less digits than its factorization.

1287977864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160997239 (or 160997235 counting only the distinct ones).

The product of its digits is 9483264, while the sum is 59.

The square root of 1287977864 is about 35888.4084907648. The cubic root of 1287977864 is about 1088.0181319967.

The spelling of 1287977864 in words is "one billion, two hundred eighty-seven million, nine hundred seventy-seven thousand, eight hundred sixty-four".