1983581 has 4 divisors (see below), whose sum is σ = 2088000. Its totient is φ = 1879164.

The previous prime is 1983563. The next prime is 1983587. The reversal of 1983581 is 1853891.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1853891 = 13 ⋅142607.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1983581 is a prime.

It is a super-2 number, since 2×1983581² = 7869187167122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1983587) 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 3 ways as a sum of consecutive naturals, for example, 52181 + ... + 52218.

It is an arithmetic number, because the mean of its divisors is an integer number (522000).

2^1983581 is an apocalyptic number.

It is an amenable number.

1983581 is a deficient number, since it is larger than the sum of its proper divisors (104419).

1983581 is a wasteful number, since it uses less digits than its factorization.

1983581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104418.

The product of its digits is 8640, while the sum is 35.

The square root of 1983581 is about 1408.3966060737. The cubic root of 1983581 is about 125.6463797841.

The spelling of 1983581 in words is "one million, nine hundred eighty-three thousand, five hundred eighty-one".