521243543 has 4 divisors (see below), whose sum is σ = 521357088. Its totient is φ = 521130000.

The previous prime is 521243539. The next prime is 521243623. The reversal of 521243543 is 345342125.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 521243543 - 2² = 521243539 is a prime.

It is a super-2 number, since 2×521243543² = 543389662238385698, 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 (521243533) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49583 + ... + 59168.

It is an arithmetic number, because the mean of its divisors is an integer number (130339272).

Almost surely, 2^521243543 is an apocalyptic number.

521243543 is a deficient number, since it is larger than the sum of its proper divisors (113545).

521243543 is a wasteful number, since it uses less digits than its factorization.

521243543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113544.

The product of its digits is 14400, while the sum is 29.

The square root of 521243543 is about 22830.7587039940. The cubic root of 521243543 is about 804.7856600496.

Adding to 521243543 its reverse (345342125), we get a palindrome (866585668).

The spelling of 521243543 in words is "five hundred twenty-one million, two hundred forty-three thousand, five hundred forty-three".