1091006440 has 16 divisors (see below), whose sum is σ = 2454764580. Its totient is φ = 436402560.

The previous prime is 1091006407. The next prime is 1091006443. The reversal of 1091006440 is 446001901.

It can be written as a sum of positive squares in 2 ways, for example, as 1068897636 + 22108804 = 32694^2 + 4702^2 .

It is not an unprimeable number, because it can be changed into a prime (1091006443) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13637541 + ... + 13637620.

Almost surely, 2^1091006440 is an apocalyptic number.

1091006440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1091006440 is an abundant number, since it is smaller than the sum of its proper divisors (1363758140).

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

1091006440 is a wasteful number, since it uses less digits than its factorization.

1091006440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27275172 (or 27275168 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 1091006440 is about 33030.3866159632. The cubic root of 1091006440 is about 1029.4591184120.

The spelling of 1091006440 in words is "one billion, ninety-one million, six thousand, four hundred forty".