2181716 has 6 divisors (see below), whose sum is σ = 3818010. Its totient is φ = 1090856.

The previous prime is 2181709. The next prime is 2181719. The reversal of 2181716 is 6171812.

It can be written as a sum of positive squares in only one way, i.e., 2114116 + 67600 = 1454^2 + 260^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2181719) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 272711 + ... + 272718.

It is an arithmetic number, because the mean of its divisors is an integer number (636335).

2^2181716 is an apocalyptic number.

It is an amenable number.

2181716 is a deficient number, since it is larger than the sum of its proper divisors (1636294).

2181716 is a wasteful number, since it uses less digits than its factorization.

2181716 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 545433 (or 545431 counting only the distinct ones).

The product of its digits is 672, while the sum is 26.

The square root of 2181716 is about 1477.0633026380. The cubic root of 2181716 is about 129.6978386590.

The spelling of 2181716 in words is "two million, one hundred eighty-one thousand, seven hundred sixteen".