981643 has 4 divisors (see below), whose sum is σ = 1057168. Its totient is φ = 906120.

The previous prime is 981637. The next prime is 981653. The reversal of 981643 is 346189.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 346189 = 67 ⋅5167.

It is a cyclic number.

It is not a de Polignac number, because 981643 - 2¹⁷ = 850571 is a prime.

It is a Duffinian number.

It is a plaindrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (981623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 37743 + ... + 37768.

It is an arithmetic number, because the mean of its divisors is an integer number (264292).

2⁹⁸¹⁶⁴³ is an apocalyptic number.

981643 is a deficient number, since it is larger than the sum of its proper divisors (75525).

981643 is a wasteful number, since it uses less digits than its factorization.

981643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75524.

The product of its digits is 5184, while the sum is 31.

The square root of 981643 is about 990.7789864546. The cubic root of 981643 is about 99.3843171254.

It can be divided in two parts, 98164 and 3, that multiplied together give a palindrome (294492).

The spelling of 981643 in words is "nine hundred eighty-one thousand, six hundred forty-three".