1994540491 has 2 divisors, whose sum is σ = 1994540492. Its totient is φ = 1994540490.

The previous prime is 1994540479. The next prime is 1994540507. The reversal of 1994540491 is 1940454991.

It is a weak prime.

It is an emirp because it is prime and its reverse (1940454991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1994540491 - 2⁹ = 1994539979 is a prime.

It is not a weakly prime, because it can be changed into another prime (1994540411) 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, 997270245 + 997270246.

It is an arithmetic number, because the mean of its divisors is an integer number (997270246).

Almost surely, 2^1994540491 is an apocalyptic number.

1994540491 is a deficient number, since it is larger than the sum of its proper divisors (1).

1994540491 is an equidigital number, since it uses as much as digits as its factorization.

1994540491 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 233280, while the sum is 46.

The square root of 1994540491 is about 44660.2786713204. The cubic root of 1994540491 is about 1258.7735801052.

The spelling of 1994540491 in words is "one billion, nine hundred ninety-four million, five hundred forty thousand, four hundred ninety-one".