1091647 has 4 divisors (see below), whose sum is σ = 1129320. Its totient is φ = 1053976.

The previous prime is 1091639. The next prime is 1091659. The reversal of 1091647 is 7461901.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7461901 = 37 ⋅201673.

It is not a de Polignac number, because 1091647 - 2³ = 1091639 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1091617) 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, 18793 + ... + 18850.

It is an arithmetic number, because the mean of its divisors is an integer number (282330).

2^1091647 is an apocalyptic number.

1091647 is a deficient number, since it is larger than the sum of its proper divisors (37673).

1091647 is an equidigital number, since it uses as much as digits as its factorization.

1091647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37672.

The product of its (nonzero) digits is 1512, while the sum is 28.

The square root of 1091647 is about 1044.8191231022. The cubic root of 1091647 is about 102.9660553617.

The spelling of 1091647 in words is "one million, ninety-one thousand, six hundred forty-seven".