1287876769 has 9 divisors (see below), whose sum is σ = 1368738931. Its totient is φ = 1211545120.

The previous prime is 1287876749. The next prime is 1287876773. The reversal of 1287876769 is 9676787821.

The square root of 1287876769 is 35887.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 1002672225 + 285204544 = 31665^2 + 16888^2 .

It is not a de Polignac number, because 1287876769 - 2⁷ = 1287876641 is a prime.

It is a super-2 number, since 2×1287876769² = 3317253144259758722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1287876719) 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 8 ways as a sum of consecutive naturals, for example, 609024 + ... + 611134.

Almost surely, 2^1287876769 is an apocalyptic number.

1287876769 is the 35887-th square number.

1287876769 is the 17944-th centered octagonal number.

It is an amenable number.

1287876769 is a deficient number, since it is larger than the sum of its proper divisors (80862162).

1287876769 is an frugal number, since it uses more digits than its factorization.

1287876769 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4256 (or 2128 counting only the distinct ones).

The product of its digits is 14224896, while the sum is 61.

The cubic root of 1287876769 is about 1087.9896646154.

The spelling of 1287876769 in words is "one billion, two hundred eighty-seven million, eight hundred seventy-six thousand, seven hundred sixty-nine".