1091631 has 8 divisors (see below), whose sum is σ = 1477504. Its totient is φ = 716760.

The previous prime is 1091627. The next prime is 1091633. The reversal of 1091631 is 1361901.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1091631 - 2² = 1091627 is a prime.

It is a super-2 number, since 2×1091631² = 2383316480322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1091598 and 1091607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1091633) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2515 + ... + 2916.

It is an arithmetic number, because the mean of its divisors is an integer number (184688).

2^1091631 is an apocalyptic number.

1091631 is a deficient number, since it is larger than the sum of its proper divisors (385873).

1091631 is an equidigital number, since it uses as much as digits as its factorization.

1091631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5501.

The product of its (nonzero) digits is 162, while the sum is 21.

The square root of 1091631 is about 1044.8114662464. The cubic root of 1091631 is about 102.9655523099.

The spelling of 1091631 in words is "one million, ninety-one thousand, six hundred thirty-one".