1281491 has 4 divisors (see below), whose sum is σ = 1337232. Its totient is φ = 1225752.

The previous prime is 1281463. The next prime is 1281503. The reversal of 1281491 is 1941821.

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-1281491 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1281491.

It is not an unprimeable number, because it can be changed into a prime (1281431) 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, 27836 + ... + 27881.

It is an arithmetic number, because the mean of its divisors is an integer number (334308).

2^1281491 is an apocalyptic number.

1281491 is a deficient number, since it is larger than the sum of its proper divisors (55741).

1281491 is an equidigital number, since it uses as much as digits as its factorization.

1281491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55740.

The product of its digits is 576, while the sum is 26.

The square root of 1281491 is about 1132.0295932528. The cubic root of 1281491 is about 108.6188466037.

The spelling of 1281491 in words is "one million, two hundred eighty-one thousand, four hundred ninety-one".