1091819 has 4 divisors (see below), whose sum is σ = 1100544. Its totient is φ = 1083096.

The previous prime is 1091809. The next prime is 1091837. The reversal of 1091819 is 9181901.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1091819 is a prime.

It is a super-2 number, since 2×1091819² = 2384137457522, 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 = 1091791 and 1091800.

It is not an unprimeable number, because it can be changed into a prime (1091809) 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, 4172 + ... + 4425.

It is an arithmetic number, because the mean of its divisors is an integer number (275136).

2^1091819 is an apocalyptic number.

1091819 is a deficient number, since it is larger than the sum of its proper divisors (8725).

1091819 is an equidigital number, since it uses as much as digits as its factorization.

1091819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8724.

The product of its (nonzero) digits is 648, while the sum is 29.

The square root of 1091819 is about 1044.9014307579. The cubic root of 1091819 is about 102.9714628581.

The spelling of 1091819 in words is "one million, ninety-one thousand, eight hundred nineteen".