1091649 has 16 divisors (see below), whose sum is σ = 1636992. Its totient is φ = 642048.

The previous prime is 1091639. The next prime is 1091659. The reversal of 1091649 is 9461901.

It is an interprime number because it is at equal distance from previous prime (1091639) and next prime (1091659).

It is not a de Polignac number, because 1091649 - 2⁴ = 1091633 is a prime.

1091649 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1091609) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 289 + ... + 1505.

It is an arithmetic number, because the mean of its divisors is an integer number (102312).

2^1091649 is an apocalyptic number.

It is an amenable number.

1091649 is a deficient number, since it is larger than the sum of its proper divisors (545343).

1091649 is a wasteful number, since it uses less digits than its factorization.

1091649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1256.

The product of its (nonzero) digits is 1944, while the sum is 30.

The square root of 1091649 is about 1044.8200802052. The cubic root of 1091649 is about 102.9661182428.

The spelling of 1091649 in words is "one million, ninety-one thousand, six hundred forty-nine".