2189685725 has 18 divisors (see below), whose sum is σ = 2767496046. Its totient is φ = 1718641600.

The previous prime is 2189685671. The next prime is 2189685727. The reversal of 2189685725 is 5275869812.

It can be written as a sum of positive squares in 9 ways, for example, as 744089284 + 1445596441 = 27278^2 + 38021^2 .

It is not a de Polignac number, because 2189685725 - 2⁶ = 2189685661 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (53).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2189685727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 54635 + ... + 85815.

Almost surely, 2^2189685725 is an apocalyptic number.

2189685725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

2189685725 is a deficient number, since it is larger than the sum of its proper divisors (577810321).

2189685725 is an equidigital number, since it uses as much as digits as its factorization.

2189685725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31297 (or 31239 counting only the distinct ones).

The product of its digits is 2419200, while the sum is 53.

The square root of 2189685725 is about 46794.0778838519. The cubic root of 2189685725 is about 1298.5557382710. Note that the first 3 decimals are identical.

The spelling of 2189685725 in words is "two billion, one hundred eighty-nine million, six hundred eighty-five thousand, seven hundred twenty-five".