521311416623 has 4 divisors (see below), whose sum is σ = 526094090280. Its totient is φ = 516528742968.

The previous prime is 521311416553. The next prime is 521311416709. The reversal of 521311416623 is 326614113125.

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 521311416623 - 2²⁸ = 521042981167 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521311416823) 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, 2391336665 + ... + 2391336882.

It is an arithmetic number, because the mean of its divisors is an integer number (131523522570).

Almost surely, 2^521311416623 is an apocalyptic number.

521311416623 is a deficient number, since it is larger than the sum of its proper divisors (4782673657).

521311416623 is a wasteful number, since it uses less digits than its factorization.

521311416623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4782673656.

The product of its digits is 25920, while the sum is 35.

Adding to 521311416623 its reverse (326614113125), we get a palindrome (847925529748).

The spelling of 521311416623 in words is "five hundred twenty-one billion, three hundred eleven million, four hundred sixteen thousand, six hundred twenty-three".