1298743891 has 2 divisors, whose sum is σ = 1298743892. Its totient is φ = 1298743890.

The previous prime is 1298743871. The next prime is 1298743909. The reversal of 1298743891 is 1983478921.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1298743891 - 2⁷ = 1298743763 is a prime.

It is not a weakly prime, because it can be changed into another prime (1298743861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 649371945 + 649371946.

It is an arithmetic number, because the mean of its divisors is an integer number (649371946).

Almost surely, 2^1298743891 is an apocalyptic number.

1298743891 is a deficient number, since it is larger than the sum of its proper divisors (1).

1298743891 is an equidigital number, since it uses as much as digits as its factorization.

1298743891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 870912, while the sum is 52.

The square root of 1298743891 is about 36038.0894471391. The cubic root of 1298743891 is about 1091.0412548044.

The spelling of 1298743891 in words is "one billion, two hundred ninety-eight million, seven hundred forty-three thousand, eight hundred ninety-one".