1291244947 has 2 divisors, whose sum is σ = 1291244948. Its totient is φ = 1291244946.

The previous prime is 1291244881. The next prime is 1291244963. The reversal of 1291244947 is 7494421921.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1291244947 - 2¹¹ = 1291242899 is a prime.

It is not a weakly prime, because it can be changed into another prime (1291244987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 645622473 + 645622474.

It is an arithmetic number, because the mean of its divisors is an integer number (645622474).

Almost surely, 2^1291244947 is an apocalyptic number.

1291244947 is a deficient number, since it is larger than the sum of its proper divisors (1).

1291244947 is an equidigital number, since it uses as much as digits as its factorization.

1291244947 is an evil number, because the sum of its binary digits is even.

The product of its digits is 145152, while the sum is 43.

The square root of 1291244947 is about 35933.8969080727. The cubic root of 1291244947 is about 1088.9373103720.

The spelling of 1291244947 in words is "one billion, two hundred ninety-one million, two hundred forty-four thousand, nine hundred forty-seven".