1491273817 has 12 divisors (see below), whose sum is σ = 1692049408. Its totient is φ = 1311967800.

The previous prime is 1491273803. The next prime is 1491273821. The reversal of 1491273817 is 7183721941.

It is a de Polignac number, because none of the positive numbers 2^k-1491273817 is a prime.

It is a hoax number, since the sum of its digits (43) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1491273827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 195033 + ... + 202534.

Almost surely, 2^1491273817 is an apocalyptic number.

It is an amenable number.

1491273817 is a deficient number, since it is larger than the sum of its proper divisors (200775591).

1491273817 is a wasteful number, since it uses less digits than its factorization.

1491273817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 397620 (or 397609 counting only the distinct ones).

The product of its digits is 84672, while the sum is 43.

The square root of 1491273817 is about 38617.0146049640. The cubic root of 1491273817 is about 1142.4901494489.

The spelling of 1491273817 in words is "one billion, four hundred ninety-one million, two hundred seventy-three thousand, eight hundred seventeen".