1287311291 has 6 divisors (see below), whose sum is σ = 1497484620. Its totient is φ = 1103409636.

The previous prime is 1287311269. The next prime is 1287311293. The reversal of 1287311291 is 1921137821.

It is not a de Polignac number, because 1287311291 - 2⁶ = 1287311227 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1287311293) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 13135781 + ... + 13135878.

It is an arithmetic number, because the mean of its divisors is an integer number (249580770).

Almost surely, 2^1287311291 is an apocalyptic number.

1287311291 is a deficient number, since it is larger than the sum of its proper divisors (210173329).

1287311291 is an equidigital number, since it uses as much as digits as its factorization.

1287311291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26271673 (or 26271666 counting only the distinct ones).

The product of its digits is 6048, while the sum is 35.

The square root of 1287311291 is about 35879.1205438483. The cubic root of 1287311291 is about 1087.8304039621.

The spelling of 1287311291 in words is "one billion, two hundred eighty-seven million, three hundred eleven thousand, two hundred ninety-one".