1491494491 has 2 divisors, whose sum is σ = 1491494492. Its totient is φ = 1491494490.

The previous prime is 1491494489. The next prime is 1491494527. The reversal of 1491494491 is 1944941941.

It is a happy number.

It is a weak prime.

It is an emirp because it is prime and its reverse (1944941941) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1491494491 - 2¹ = 1491494489 is a prime.

Together with 1491494489, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1491494401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 745747245 + 745747246.

It is an arithmetic number, because the mean of its divisors is an integer number (745747246).

Almost surely, 2^1491494491 is an apocalyptic number.

1491494491 is a deficient number, since it is larger than the sum of its proper divisors (1).

1491494491 is an equidigital number, since it uses as much as digits as its factorization.

1491494491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 186624, while the sum is 46.

The square root of 1491494491 is about 38619.8717113353. The cubic root of 1491494491 is about 1142.5465007001.

The spelling of 1491494491 in words is "one billion, four hundred ninety-one million, four hundred ninety-four thousand, four hundred ninety-one".