1298721841 has 4 divisors (see below), whose sum is σ = 1355188032. Its totient is φ = 1242255652.

The previous prime is 1298721829. The next prime is 1298721889. The reversal of 1298721841 is 1481278921.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1298721841 - 2⁷ = 1298721713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1298721821) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28233061 + ... + 28233106.

It is an arithmetic number, because the mean of its divisors is an integer number (338797008).

Almost surely, 2^1298721841 is an apocalyptic number.

It is an amenable number.

1298721841 is a deficient number, since it is larger than the sum of its proper divisors (56466191).

1298721841 is an equidigital number, since it uses as much as digits as its factorization.

1298721841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56466190.

The product of its digits is 64512, while the sum is 43.

The square root of 1298721841 is about 36037.7835195230. The cubic root of 1298721841 is about 1091.0350802240.

The spelling of 1298721841 in words is "one billion, two hundred ninety-eight million, seven hundred twenty-one thousand, eight hundred forty-one".