861606144 has 216 divisors, whose sum is σ = 2910590592. Its totient is φ = 239984640.

The previous prime is 861606143. The next prime is 861606149. The reversal of 861606144 is 441606168.

861606144 is a `hidden beast` number, since 8 + 6 + 1 + 606 + 1 + 44 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 861606099 and 861606108.

It is not an unprimeable number, because it can be changed into a prime (861606143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 660597 + ... + 661899.

Almost surely, 2^861606144 is an apocalyptic number.

861606144 is a gapful number since it is divisible by the number (84) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 861606144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1455295296).

861606144 is an abundant number, since it is smaller than the sum of its proper divisors (2048984448).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

861606144 is a wasteful number, since it uses less digits than its factorization.

861606144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1373 (or 1356 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 861606144 is about 29353.1283511656. The cubic root of 861606144 is about 951.5601857030.

The spelling of 861606144 in words is "eight hundred sixty-one million, six hundred six thousand, one hundred forty-four".