2180749 has 4 divisors (see below), whose sum is σ = 2233980. Its totient is φ = 2127520.

The previous prime is 2180747. The next prime is 2180797. The reversal of 2180749 is 9470812.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1170724 + 1010025 = 1082^2 + 1005^2 .

It is a cyclic number.

It is not a de Polignac number, because 2180749 - 2¹ = 2180747 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2180749.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2180741) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26554 + ... + 26635.

It is an arithmetic number, because the mean of its divisors is an integer number (558495).

2^2180749 is an apocalyptic number.

It is an amenable number.

2180749 is a deficient number, since it is larger than the sum of its proper divisors (53231).

2180749 is an equidigital number, since it uses as much as digits as its factorization.

2180749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53230.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 2180749 is about 1476.7359276458. The cubic root of 2180749 is about 129.6786738756.

The spelling of 2180749 in words is "two million, one hundred eighty thousand, seven hundred forty-nine".