1685557297 has 2 divisors, whose sum is σ = 1685557298. Its totient is φ = 1685557296.

The previous prime is 1685557243. The next prime is 1685557331. The reversal of 1685557297 is 7927555861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1228923136 + 456634161 = 35056^2 + 21369^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1685557297 is a prime.

It is a super-2 number, since 2×1685557297² = 5682206802939892418, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1685557207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 842778648 + 842778649.

It is an arithmetic number, because the mean of its divisors is an integer number (842778649).

Almost surely, 2^1685557297 is an apocalyptic number.

It is an amenable number.

1685557297 is a deficient number, since it is larger than the sum of its proper divisors (1).

1685557297 is an equidigital number, since it uses as much as digits as its factorization.

1685557297 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5292000, while the sum is 55.

The square root of 1685557297 is about 41055.5391756094. The cubic root of 1685557297 is about 1190.0937470575.

The spelling of 1685557297 in words is "one billion, six hundred eighty-five million, five hundred fifty-seven thousand, two hundred ninety-seven".