1285385681 has 4 divisors (see below), whose sum is σ = 1294633200. Its totient is φ = 1276138164.

The previous prime is 1285385677. The next prime is 1285385707. The reversal of 1285385681 is 1865835821.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1285385681 - 2² = 1285385677 is a prime.

It is a super-2 number, since 2×1285385681² = 3304432697839667522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1285345681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4623551 + ... + 4623828.

It is an arithmetic number, because the mean of its divisors is an integer number (323658300).

Almost surely, 2^1285385681 is an apocalyptic number.

It is an amenable number.

1285385681 is a deficient number, since it is larger than the sum of its proper divisors (9247519).

1285385681 is an equidigital number, since it uses as much as digits as its factorization.

1285385681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9247518.

The product of its digits is 460800, while the sum is 47.

The square root of 1285385681 is about 35852.2758133985. The cubic root of 1285385681 is about 1087.2877270274.

The spelling of 1285385681 in words is "one billion, two hundred eighty-five million, three hundred eighty-five thousand, six hundred eighty-one".