2181724 has 12 divisors (see below), whose sum is σ = 3858064. Its totient is φ = 1079424.

The previous prime is 2181719. The next prime is 2181731. The reversal of 2181724 is 4271812.

It is a happy number.

It is a super-2 number, since 2×2181724² = 9519839224352, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2424 + ... + 3199.

2^2181724 is an apocalyptic number.

It is an amenable number.

2181724 is a deficient number, since it is larger than the sum of its proper divisors (1676340).

2181724 is a wasteful number, since it uses less digits than its factorization.

2181724 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5724 (or 5722 counting only the distinct ones).

The product of its digits is 896, while the sum is 25.

The square root of 2181724 is about 1477.0660107118. The cubic root of 2181724 is about 129.6979971858.

The spelling of 2181724 in words is "two million, one hundred eighty-one thousand, seven hundred twenty-four".