791123821 has 2 divisors, whose sum is σ = 791123822. Its totient is φ = 791123820.

The previous prime is 791123771. The next prime is 791123831. The reversal of 791123821 is 128321197.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 674181225 + 116942596 = 25965^2 + 10814^2 .

It is an emirp because it is prime and its reverse (128321197) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 791123821 - 2¹⁷ = 790992749 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (791123831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 395561910 + 395561911.

It is an arithmetic number, because the mean of its divisors is an integer number (395561911).

Almost surely, 2^791123821 is an apocalyptic number.

It is an amenable number.

791123821 is a deficient number, since it is larger than the sum of its proper divisors (1).

791123821 is an equidigital number, since it uses as much as digits as its factorization.

791123821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6048, while the sum is 34.

The square root of 791123821 is about 28126.9234186749. The cubic root of 791123821 is about 924.8716923565.

The spelling of 791123821 in words is "seven hundred ninety-one million, one hundred twenty-three thousand, eight hundred twenty-one".