1921985 has 8 divisors (see below), whose sum is σ = 2483880. Its totient is φ = 1419264.

The previous prime is 1921981. The next prime is 1922027. The reversal of 1921985 is 5891291.

It can be written as a sum of positive squares in 4 ways, for example, as 39601 + 1882384 = 199^2 + 1372^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1921985 - 2² = 1921981 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1921981) 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 7 ways as a sum of consecutive naturals, for example, 14720 + ... + 14849.

It is an arithmetic number, because the mean of its divisors is an integer number (310485).

2^1921985 is an apocalyptic number.

It is an amenable number.

1921985 is a deficient number, since it is larger than the sum of its proper divisors (561895).

1921985 is a wasteful number, since it uses less digits than its factorization.

1921985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29587.

The product of its digits is 6480, while the sum is 35.

The square root of 1921985 is about 1386.3567361974. The cubic root of 1921985 is about 124.3321178228.

The spelling of 1921985 in words is "one million, nine hundred twenty-one thousand, nine hundred eighty-five".