8156318257 has 2 divisors, whose sum is σ = 8156318258. Its totient is φ = 8156318256.

The previous prime is 8156318197. The next prime is 8156318281. The reversal of 8156318257 is 7528136518.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7590068641 + 566249616 = 87121^2 + 23796^2 .

It is a cyclic number.

It is not a de Polignac number, because 8156318257 - 2⁷ = 8156318129 is a prime.

It is not a weakly prime, because it can be changed into another prime (8156318057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4078159128 + 4078159129.

It is an arithmetic number, because the mean of its divisors is an integer number (4078159129).

Almost surely, 2^8156318257 is an apocalyptic number.

It is an amenable number.

8156318257 is a deficient number, since it is larger than the sum of its proper divisors (1).

8156318257 is an equidigital number, since it uses as much as digits as its factorization.

8156318257 is an evil number, because the sum of its binary digits is even.

The product of its digits is 403200, while the sum is 46.

The square root of 8156318257 is about 90312.3372358395. The cubic root of 8156318257 is about 2012.9425854888.

The spelling of 8156318257 in words is "eight billion, one hundred fifty-six million, three hundred eighteen thousand, two hundred fifty-seven".