2166644 has 6 divisors (see below), whose sum is σ = 3791634. Its totient is φ = 1083320.

The previous prime is 2166629. The next prime is 2166673. The reversal of 2166644 is 4466612.

It can be written as a sum of positive squares in only one way, i.e., 1926544 + 240100 = 1388^2 + 490^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 270827 + ... + 270834.

It is an arithmetic number, because the mean of its divisors is an integer number (631939).

2^2166644 is an apocalyptic number.

It is an amenable number.

2166644 is a deficient number, since it is larger than the sum of its proper divisors (1624990).

2166644 is a wasteful number, since it uses less digits than its factorization.

2166644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 541665 (or 541663 counting only the distinct ones).

The product of its digits is 6912, while the sum is 29.

The square root of 2166644 is about 1471.9524448840. The cubic root of 2166644 is about 129.3984833721.

Subtracting 2166644 from its reverse (4466612), we obtain a cube (2299968 = 132³).

The spelling of 2166644 in words is "two million, one hundred sixty-six thousand, six hundred forty-four".