2178725 has 6 divisors (see below), whose sum is σ = 2701650. Its totient is φ = 1742960.

The previous prime is 2178719. The next prime is 2178731. The reversal of 2178725 is 5278712.

2178725 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (2178719) and next prime (2178731).

It can be written as a sum of positive squares in 3 ways, for example, as 14884 + 2163841 = 122^2 + 1471^2 .

It is not a de Polignac number, because 2178725 - 2¹² = 2174629 is a prime.

It is a plaindrome in base 11.

It is a junction number, because it is equal to n+sod(n) for n = 2178691 and 2178700.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 43550 + ... + 43599.

It is an arithmetic number, because the mean of its divisors is an integer number (450275).

2^2178725 is an apocalyptic number.

2178725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

2178725 is a deficient number, since it is larger than the sum of its proper divisors (522925).

2178725 is an equidigital number, since it uses as much as digits as its factorization.

2178725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87159 (or 87154 counting only the distinct ones).

The product of its digits is 7840, while the sum is 32.

The square root of 2178725 is about 1476.0504733917. The cubic root of 2178725 is about 129.6385422695.

It can be divided in two parts, 21787 and 25, that added together give a palindrome (21812).

The spelling of 2178725 in words is "two million, one hundred seventy-eight thousand, seven hundred twenty-five".