1091391812 has 24 divisors (see below), whose sum is σ = 2241779904. Its totient is φ = 455097312.

The previous prime is 1091391799. The next prime is 1091391839. The reversal of 1091391812 is 2181931901.

It is a super-2 number, since 2×1091391812² = 2382272174601286688, which contains 22 as substring.

It is a zygodrome in base 3.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 525698 + ... + 527769.

It is an arithmetic number, because the mean of its divisors is an integer number (93407496).

Almost surely, 2^1091391812 is an apocalyptic number.

It is an amenable number.

1091391812 is an abundant number, since it is smaller than the sum of its proper divisors (1150388092).

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

1091391812 is a wasteful number, since it uses less digits than its factorization.

1091391812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1053515 (or 1053513 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 35.

The square root of 1091391812 is about 33036.2196989910. The cubic root of 1091391812 is about 1029.5803147688.

The spelling of 1091391812 in words is "one billion, ninety-one million, three hundred ninety-one thousand, eight hundred twelve".