1285856137 has 2 divisors, whose sum is σ = 1285856138. Its totient is φ = 1285856136.

The previous prime is 1285856119. The next prime is 1285856167. The reversal of 1285856137 is 7316585821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1285652736 + 203401 = 35856^2 + 451^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1285856137 is a prime.

It is not a weakly prime, because it can be changed into another prime (1285856167) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 642928068 + 642928069.

It is an arithmetic number, because the mean of its divisors is an integer number (642928069).

Almost surely, 2^1285856137 is an apocalyptic number.

It is an amenable number.

1285856137 is a deficient number, since it is larger than the sum of its proper divisors (1).

1285856137 is an equidigital number, since it uses as much as digits as its factorization.

1285856137 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 1285856137 is about 35858.8362471511. The cubic root of 1285856137 is about 1087.4203613148.

The spelling of 1285856137 in words is "one billion, two hundred eighty-five million, eight hundred fifty-six thousand, one hundred thirty-seven".