1678811513 has 2 divisors, whose sum is σ = 1678811514. Its totient is φ = 1678811512.

The previous prime is 1678811509. The next prime is 1678811531. The reversal of 1678811513 is 3151188761.

1678811513 = 28972² + 28973².

Together with next prime (1678811531) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 839434729 + 839376784 = 28973^2 + 28972^2 .

It is a cyclic number.

It is not a de Polignac number, because 1678811513 - 2² = 1678811509 is a prime.

It is not a weakly prime, because it can be changed into another prime (1678811503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 839405756 + 839405757.

It is an arithmetic number, because the mean of its divisors is an integer number (839405757).

Almost surely, 2^1678811513 is an apocalyptic number.

1678811513 is the 28973-rd centered square number.

It is an amenable number.

1678811513 is a deficient number, since it is larger than the sum of its proper divisors (1).

1678811513 is an equidigital number, since it uses as much as digits as its factorization.

1678811513 is an evil number, because the sum of its binary digits is even.

The product of its digits is 40320, while the sum is 41.

The square root of 1678811513 is about 40973.3024419560. The cubic root of 1678811513 is about 1188.5039960900.

The spelling of 1678811513 in words is "one billion, six hundred seventy-eight million, eight hundred eleven thousand, five hundred thirteen".