861504 has 56 divisors (see below), whose sum is σ = 2609088. Its totient is φ = 245760.

The previous prime is 861499. The next prime is 861541. The reversal of 861504 is 405168.

It is a tau number, because it is divible by the number of its divisors (56).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1024 + ... + 1664.

2⁸⁶¹⁵⁰⁴ is an apocalyptic number.

861504 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 861504, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1304544).

861504 is an abundant number, since it is smaller than the sum of its proper divisors (1747584).

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

861504 is a wasteful number, since it uses less digits than its factorization.

861504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 663 (or 653 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 861504 is about 928.1723977796. The cubic root of 861504 is about 95.1522581512.

The spelling of 861504 in words is "eight hundred sixty-one thousand, five hundred four".