1091287812 has 12 divisors (see below), whose sum is σ = 2546338256. Its totient is φ = 363762600.

The previous prime is 1091287807. The next prime is 1091287853. The reversal of 1091287812 is 2187821901.

It is a tau number, because it is divible by the number of its divisors (12).

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45470314 + ... + 45470337.

Almost surely, 2^1091287812 is an apocalyptic number.

1091287812 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1091287812 is an abundant number, since it is smaller than the sum of its proper divisors (1455050444).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1091287812 is a wasteful number, since it uses less digits than its factorization.

1091287812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90940658 (or 90940656 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 39.

The square root of 1091287812 is about 33034.6456315184. The cubic root of 1091287812 is about 1029.5476104265.

The spelling of 1091287812 in words is "one billion, ninety-one million, two hundred eighty-seven thousand, eight hundred twelve".