6721318057 has 2 divisors, whose sum is σ = 6721318058. Its totient is φ = 6721318056.

The previous prime is 6721318027. The next prime is 6721318073. The reversal of 6721318057 is 7508131276.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3446159616 + 3275158441 = 58704^2 + 57229^2 .

It is a cyclic number.

It is not a de Polignac number, because 6721318057 - 2⁷ = 6721317929 is a prime.

It is a super-2 number, since 2×6721318057² = 90352232846708510498, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (6721318007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3360659028 + 3360659029.

It is an arithmetic number, because the mean of its divisors is an integer number (3360659029).

Almost surely, 2^6721318057 is an apocalyptic number.

It is an amenable number.

6721318057 is a deficient number, since it is larger than the sum of its proper divisors (1).

6721318057 is an equidigital number, since it uses as much as digits as its factorization.

6721318057 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 70560, while the sum is 40.

The square root of 6721318057 is about 81983.6450580236. The cubic root of 6721318057 is about 1887.2009608384.

The spelling of 6721318057 in words is "six billion, seven hundred twenty-one million, three hundred eighteen thousand, fifty-seven".