1491091 has 8 divisors (see below), whose sum is σ = 1712480. Its totient is φ = 1271808.

The previous prime is 1491079. The next prime is 1491097. The reversal of 1491091 is 1901941.

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

It is a 11-Lehmer number, since φ(1491091) divides (1491091-1)¹¹.

It is a cyclic number.

It is not a de Polignac number, because 1491091 - 2⁷ = 1490963 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1491097) 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, 1555 + ... + 2323.

It is an arithmetic number, because the mean of its divisors is an integer number (214060).

2^1491091 is an apocalyptic number.

1491091 is a deficient number, since it is larger than the sum of its proper divisors (221389).

1491091 is an equidigital number, since it uses as much as digits as its factorization.

1491091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1053.

The product of its (nonzero) digits is 324, while the sum is 25.

The square root of 1491091 is about 1221.1023708109. The cubic root of 1491091 is about 114.2443461140.

The spelling of 1491091 in words is "one million, four hundred ninety-one thousand, ninety-one".