861644160 has 384 divisors, whose sum is σ = 3301421760. Its totient is φ = 205701120.

The previous prime is 861644159. The next prime is 861644207. The reversal of 861644160 is 61446168.

861644160 is a `hidden beast` number, since 8 + 6 + 1 + 644 + 1 + 6 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2770405 + ... + 2770715.

Almost surely, 2^861644160 is an apocalyptic number.

861644160 is a gapful number since it is divisible by the number (80) 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 861644160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1650710880).

861644160 is an abundant number, since it is smaller than the sum of its proper divisors (2439777600).

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

861644160 is a wasteful number, since it uses less digits than its factorization.

861644160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 386 (or 371 counting only the distinct ones).

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

The square root of 861644160 is about 29353.7759070277. The cubic root of 861644160 is about 951.5741804887.

The spelling of 861644160 in words is "eight hundred sixty-one million, six hundred forty-four thousand, one hundred sixty".