861223185 has 40 divisors (see below), whose sum is σ = 1561233960. Its totient is φ = 454139136.

The previous prime is 861223169. The next prime is 861223229. The reversal of 861223185 is 581322168.

It is a happy number.

861223185 is a `hidden beast` number, since 8 + 612 + 2 + 31 + 8 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 134165889 + 727057296 = 11583^2 + 26964^2 .

It is not a de Polignac number, because 861223185 - 2⁴ = 861223169 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 24099 + ... + 47991.

It is an arithmetic number, because the mean of its divisors is an integer number (39030849).

Almost surely, 2^861223185 is an apocalyptic number.

It is an amenable number.

861223185 is a deficient number, since it is larger than the sum of its proper divisors (700010775).

861223185 is a wasteful number, since it uses less digits than its factorization.

861223185 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23999 (or 23990 counting only the distinct ones).

The product of its digits is 23040, while the sum is 36.

The square root of 861223185 is about 29346.6043180467. The cubic root of 861223185 is about 951.4191844877.

The spelling of 861223185 in words is "eight hundred sixty-one million, two hundred twenty-three thousand, one hundred eighty-five".