861408 has 48 divisors (see below), whose sum is σ = 2514960. Its totient is φ = 286848.

The previous prime is 861391. The next prime is 861433. The reversal of 861408 is 804168.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

861408 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 366 + ... + 1362.

It is an arithmetic number, because the mean of its divisors is an integer number (52395).

2⁸⁶¹⁴⁰⁸ 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 861408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1257480).

861408 is an abundant number, since it is smaller than the sum of its proper divisors (1653552).

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

861408 is a wasteful number, since it uses less digits than its factorization.

861408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1016 (or 1002 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 861408 is about 928.1206818081. The cubic root of 861408 is about 95.1487236519.

It can be divided in two parts, 8 and 61408, that added together give a palindrome (61416).

The spelling of 861408 in words is "eight hundred sixty-one thousand, four hundred eight".