2190645 has 28 divisors (see below), whose sum is σ = 3947916. Its totient is φ = 1166400.

The previous prime is 2190613. The next prime is 2190647. The reversal of 2190645 is 5460912.

2190645 is a `hidden beast` number, since 2 + 19 + 0 + 645 = 666.

2190645 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 1347921 + 842724 = 1161^2 + 918^2 .

It is not a de Polignac number, because 2190645 - 2⁵ = 2190613 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2190647) by changing a digit.

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 27 ways as a sum of consecutive naturals, for example, 3345 + ... + 3945.

It is an arithmetic number, because the mean of its divisors is an integer number (140997).

2^2190645 is an apocalyptic number.

It is an amenable number.

2190645 is a deficient number, since it is larger than the sum of its proper divisors (1757271).

2190645 is an frugal number, since it uses more digits than its factorization.

2190645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 624 (or 609 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 2190645 is about 1480.0827679559. The cubic root of 2190645 is about 129.8745337807.

The spelling of 2190645 in words is "two million, one hundred ninety thousand, six hundred forty-five".