1287771 has 16 divisors (see below), whose sum is σ = 1809408. Its totient is φ = 813600.

The previous prime is 1287761. The next prime is 1287787. The reversal of 1287771 is 1777821.

It is not a de Polignac number, because 1287771 - 2⁵ = 1287739 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1287731) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5560 + ... + 5786.

It is an arithmetic number, because the mean of its divisors is an integer number (113088).

2^1287771 is an apocalyptic number.

1287771 is a deficient number, since it is larger than the sum of its proper divisors (521637).

1287771 is a wasteful number, since it uses less digits than its factorization.

1287771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322.

The product of its digits is 5488, while the sum is 33.

The square root of 1287771 is about 1134.7999823757. The cubic root of 1287771 is about 108.7959879486.

It can be divided in two parts, 128777 and 1, that added together give a triangular number (128778 = T₅₀₇).

The spelling of 1287771 in words is "one million, two hundred eighty-seven thousand, seven hundred seventy-one".