791740721 has 2 divisors, whose sum is σ = 791740722. Its totient is φ = 791740720.

The previous prime is 791740679. The next prime is 791740727. The reversal of 791740721 is 127047197.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 500014321 + 291726400 = 22361^2 + 17080^2 .

It is an emirp because it is prime and its reverse (127047197) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 791740721 - 2⁶ = 791740657 is a prime.

It is a super-5 number, since 5×791740721⁵ (a number of 46 digits) contains 55555 as substring.

It is not a weakly prime, because it can be changed into another prime (791740727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 395870360 + 395870361.

It is an arithmetic number, because the mean of its divisors is an integer number (395870361).

Almost surely, 2^791740721 is an apocalyptic number.

It is an amenable number.

791740721 is a deficient number, since it is larger than the sum of its proper divisors (1).

791740721 is an equidigital number, since it uses as much as digits as its factorization.

791740721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24696, while the sum is 38.

The square root of 791740721 is about 28137.8876428207. The cubic root of 791740721 is about 925.1120277270.

The spelling of 791740721 in words is "seven hundred ninety-one million, seven hundred forty thousand, seven hundred twenty-one".