1491087729 has 4 divisors (see below), whose sum is σ = 1988116976. Its totient is φ = 994058484.

The previous prime is 1491087727. The next prime is 1491087733. The reversal of 1491087729 is 9277801941.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1491087729 - 2¹ = 1491087727 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1491087727) 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 3 ways as a sum of consecutive naturals, for example, 248514619 + ... + 248514624.

It is an arithmetic number, because the mean of its divisors is an integer number (497029244).

Almost surely, 2^1491087729 is an apocalyptic number.

It is an amenable number.

1491087729 is a deficient number, since it is larger than the sum of its proper divisors (497029247).

1491087729 is an equidigital number, since it uses as much as digits as its factorization.

1491087729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 497029246.

The product of its (nonzero) digits is 254016, while the sum is 48.

The square root of 1491087729 is about 38614.6051255221. The cubic root of 1491087729 is about 1142.4426257484.

The spelling of 1491087729 in words is "one billion, four hundred ninety-one million, eighty-seven thousand, seven hundred twenty-nine".