521144643 has 4 divisors (see below), whose sum is σ = 694859528. Its totient is φ = 347429760.

The previous prime is 521144629. The next prime is 521144651. The reversal of 521144643 is 346441125.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 521144643 - 2⁶ = 521144579 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 521144643.

It is not an unprimeable number, because it can be changed into a prime (521144623) 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, 86857438 + ... + 86857443.

It is an arithmetic number, because the mean of its divisors is an integer number (173714882).

Almost surely, 2^521144643 is an apocalyptic number.

521144643 is a deficient number, since it is larger than the sum of its proper divisors (173714885).

521144643 is a wasteful number, since it uses less digits than its factorization.

521144643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173714884.

The product of its digits is 11520, while the sum is 30.

The square root of 521144643 is about 22828.5926635875. The cubic root of 521144643 is about 804.7347572055.

Adding to 521144643 its reverse (346441125), we get a palindrome (867585768).

The spelling of 521144643 in words is "five hundred twenty-one million, one hundred forty-four thousand, six hundred forty-three".