861205605 has 64 divisors (see below), whose sum is σ = 1558690560. Its totient is φ = 403070976.

The previous prime is 861205589. The next prime is 861205627. The reversal of 861205605 is 506502168.

It is not a de Polignac number, because 861205605 - 2⁴ = 861205589 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 377749 + ... + 380021.

It is an arithmetic number, because the mean of its divisors is an integer number (24354540).

Almost surely, 2^861205605 is an apocalyptic number.

It is an amenable number.

861205605 is a deficient number, since it is larger than the sum of its proper divisors (697484955).

861205605 is a wasteful number, since it uses less digits than its factorization.

861205605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2390.

The product of its (nonzero) digits is 14400, while the sum is 33.

The square root of 861205605 is about 29346.3047929377. The cubic root of 861205605 is about 951.4127107252.

The spelling of 861205605 in words is "eight hundred sixty-one million, two hundred five thousand, six hundred five".