1921565 has 16 divisors (see below), whose sum is σ = 2462400. Its totient is φ = 1435392.

The previous prime is 1921559. The next prime is 1921573. The reversal of 1921565 is 5651291.

It is a cyclic number.

It is not a de Polignac number, because 1921565 - 2¹⁴ = 1905181 is a prime.

It is a Curzon number.

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 15 ways as a sum of consecutive naturals, for example, 10646 + ... + 10824.

It is an arithmetic number, because the mean of its divisors is an integer number (153900).

2^1921565 is an apocalyptic number.

It is an amenable number.

1921565 is a deficient number, since it is larger than the sum of its proper divisors (540835).

1921565 is a wasteful number, since it uses less digits than its factorization.

1921565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 316.

The product of its digits is 2700, while the sum is 29.

The square root of 1921565 is about 1386.2052517575. The cubic root of 1921565 is about 124.3230606426.

The spelling of 1921565 in words is "one million, nine hundred twenty-one thousand, five hundred sixty-five".