851517257 has 2 divisors, whose sum is σ = 851517258. Its totient is φ = 851517256.

The previous prime is 851517253. The next prime is 851517259. The reversal of 851517257 is 752715158.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 547747216 + 303770041 = 23404^2 + 17429^2 .

It is a cyclic number.

It is not a de Polignac number, because 851517257 - 2² = 851517253 is a prime.

Together with 851517259, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (851517253) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 425758628 + 425758629.

It is an arithmetic number, because the mean of its divisors is an integer number (425758629).

Almost surely, 2^851517257 is an apocalyptic number.

It is an amenable number.

851517257 is a deficient number, since it is larger than the sum of its proper divisors (1).

851517257 is an equidigital number, since it uses as much as digits as its factorization.

851517257 is an evil number, because the sum of its binary digits is even.

The product of its digits is 98000, while the sum is 41.

The square root of 851517257 is about 29180.7686156482. The cubic root of 851517257 is about 947.8315293598.

The spelling of 851517257 in words is "eight hundred fifty-one million, five hundred seventeen thousand, two hundred fifty-seven".