1491312731 has 2 divisors, whose sum is σ = 1491312732. Its totient is φ = 1491312730.

The previous prime is 1491312703. The next prime is 1491312853. The reversal of 1491312731 is 1372131941.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1491312731 - 2¹⁴ = 1491296347 is a prime.

It is a super-2 number, since 2×1491312731² = 4448027323285356722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1491312701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 745656365 + 745656366.

It is an arithmetic number, because the mean of its divisors is an integer number (745656366).

Almost surely, 2^1491312731 is an apocalyptic number.

1491312731 is a deficient number, since it is larger than the sum of its proper divisors (1).

1491312731 is an equidigital number, since it uses as much as digits as its factorization.

1491312731 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4536, while the sum is 32.

The square root of 1491312731 is about 38617.5184469432. The cubic root of 1491312731 is about 1142.5000869208.

The spelling of 1491312731 in words is "one billion, four hundred ninety-one million, three hundred twelve thousand, seven hundred thirty-one".