1286713661 has 2 divisors, whose sum is σ = 1286713662. Its totient is φ = 1286713660.

The previous prime is 1286713601. The next prime is 1286713693. The reversal of 1286713661 is 1663176821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1282069636 + 4644025 = 35806^2 + 2155^2 .

It is an emirp because it is prime and its reverse (1663176821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1286713661 - 2²⁶ = 1219604797 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1286713601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 643356830 + 643356831.

It is an arithmetic number, because the mean of its divisors is an integer number (643356831).

Almost surely, 2^1286713661 is an apocalyptic number.

It is an amenable number.

1286713661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1286713661 is an equidigital number, since it uses as much as digits as its factorization.

1286713661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 72576, while the sum is 41.

The square root of 1286713661 is about 35870.7911956232. The cubic root of 1286713661 is about 1087.6620373517.

The spelling of 1286713661 in words is "one billion, two hundred eighty-six million, seven hundred thirteen thousand, six hundred sixty-one".