521540122403 has 4 divisors (see below), whose sum is σ = 532636720800. Its totient is φ = 510443524008.

The previous prime is 521540122333. The next prime is 521540122429. The reversal of 521540122403 is 304221045125.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-521540122403 is a prime.

It is a super-2 number, since 2×521540122403² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (521540122483) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5548299128 + ... + 5548299221.

It is an arithmetic number, because the mean of its divisors is an integer number (133159180200).

Almost surely, 2^521540122403 is an apocalyptic number.

521540122403 is a deficient number, since it is larger than the sum of its proper divisors (11096598397).

521540122403 is a wasteful number, since it uses less digits than its factorization.

521540122403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11096598396.

The product of its (nonzero) digits is 9600, while the sum is 29.

Adding to 521540122403 its reverse (304221045125), we get a palindrome (825761167528).

The spelling of 521540122403 in words is "five hundred twenty-one billion, five hundred forty million, one hundred twenty-two thousand, four hundred three".