861140448 has 144 divisors (see below), whose sum is σ = 2834657280. Its totient is φ = 242880768.

The previous prime is 861140431. The next prime is 861140453. The reversal of 861140448 is 844041168.

It is a tau number, because it is divible by the number of its divisors (144).

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 pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 156561 + ... + 161967.

It is an arithmetic number, because the mean of its divisors is an integer number (19685120).

Almost surely, 2^861140448 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 861140448, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1417328640).

861140448 is an abundant number, since it is smaller than the sum of its proper divisors (1973516832).

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

861140448 is a wasteful number, since it uses less digits than its factorization.

861140448 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5509 (or 5498 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 36.

The square root of 861140448 is about 29345.1946321710. The cubic root of 861140448 is about 951.3887161603.

The spelling of 861140448 in words is "eight hundred sixty-one million, one hundred forty thousand, four hundred forty-eight".