1020805685 has 8 divisors (see below), whose sum is σ = 1289438880. Its totient is φ = 773663184.

The previous prime is 1020805673. The next prime is 1020805697. The reversal of 1020805685 is 5865080201.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1020805673) and next prime (1020805697).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1020805685 - 2²⁴ = 1004028469 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5372567 + ... + 5372756.

It is an arithmetic number, because the mean of its divisors is an integer number (161179860).

Almost surely, 2^1020805685 is an apocalyptic number.

It is an amenable number.

1020805685 is a deficient number, since it is larger than the sum of its proper divisors (268633195).

1020805685 is a wasteful number, since it uses less digits than its factorization.

1020805685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10745347.

The product of its (nonzero) digits is 19200, while the sum is 35.

The square root of 1020805685 is about 31950.0498434666. The cubic root of 1020805685 is about 1006.8876792899.

Adding to 1020805685 its reverse (5865080201), we get a palindrome (6885885886).

The spelling of 1020805685 in words is "one billion, twenty million, eight hundred five thousand, six hundred eighty-five".