2161404 has 60 divisors (see below), whose sum is σ = 6464304. Its totient is φ = 616896.

The previous prime is 2161373. The next prime is 2161409. The reversal of 2161404 is 4041612.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1792 + ... + 2744.

2^2161404 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 2161404, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3232152).

2161404 is an abundant number, since it is smaller than the sum of its proper divisors (4302900).

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

2161404 is a wasteful number, since it uses less digits than its factorization.

2161404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 976 (or 965 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 2161404 is about 1470.1714185768. The cubic root of 2161404 is about 129.2940829867.

It can be divided in two parts, 21 and 61404, that added together give a triangular number (61425 = T₃₅₀).

The spelling of 2161404 in words is "two million, one hundred sixty-one thousand, four hundred four".