1285706866 has 4 divisors (see below), whose sum is σ = 1928560302. Its totient is φ = 642853432.

The previous prime is 1285706833. The next prime is 1285706869. The reversal of 1285706866 is 6686075821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 6686075821 = 59 ⋅113323319.

It can be written as a sum of positive squares in only one way, i.e., 1269425641 + 16281225 = 35629^2 + 4035^2 .

It is not an unprimeable number, because it can be changed into a prime (1285706869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321426715 + ... + 321426718.

Almost surely, 2^1285706866 is an apocalyptic number.

1285706866 is a deficient number, since it is larger than the sum of its proper divisors (642853436).

1285706866 is an equidigital number, since it uses as much as digits as its factorization.

1285706866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 642853435.

The product of its (nonzero) digits is 967680, while the sum is 49.

The square root of 1285706866 is about 35856.7548169100. The cubic root of 1285706866 is about 1087.3782812818.

The spelling of 1285706866 in words is "one billion, two hundred eighty-five million, seven hundred six thousand, eight hundred sixty-six".