1921765 has 16 divisors (see below), whose sum is σ = 2550528. Its totient is φ = 1382656.

The previous prime is 1921763. The next prime is 1921769. The reversal of 1921765 is 5671291.

It is a cyclic number.

It is not a de Polignac number, because 1921765 - 2¹ = 1921763 is a prime.

It is a Duffinian number.

1921765 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1921763) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1464 + ... + 2446.

It is an arithmetic number, because the mean of its divisors is an integer number (159408).

2^1921765 is an apocalyptic number.

It is an amenable number.

1921765 is a deficient number, since it is larger than the sum of its proper divisors (628763).

1921765 is a wasteful number, since it uses less digits than its factorization.

1921765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1028.

The product of its digits is 3780, while the sum is 31.

The square root of 1921765 is about 1386.2773892696. The cubic root of 1921765 is about 124.3273737501.

The spelling of 1921765 in words is "one million, nine hundred twenty-one thousand, seven hundred sixty-five".